This is gonna be pretty long, but hopefully you can relate. Just a brief history from my standpoint when I made my decision; and if there's any bias that offends, then you can disregard it

Just offering up a few alternatives, and my conclusion if you care.
Me and three buddies bought Dell XPS back in 2008. 3 M1530s and a M1330.
Mine came shipped with a ****ed up hard drive, which I had replaced in the first month. In-home warranty is very nice. Dell contracts a bunch of local tech guys that do their bidding. Problem was, my 320 GB got replaced by a 250, so I called up Dell to complain. They apologized and offered to send me another tech guy, but offered me an alternative $75 cash back, which I took instead. About a year and a half in (warranty gone), the LCD went. At first, it was just the left side; the backlight seemed like it died. Then the whole thing just refused to turn on. Replacement screen (I had the 1680 x 1050 resolution, which I think is just right for a 15 inch), cost me $200+.
Second M1530 my buddy picked up, he went with the full 4 year warranty. He got the full 1080p screen, which he likes, but I think the font is almost too small. scaling it down gives bad pixelation/scaling problems. His had a faulty hard drive as well. He bought the X-Fi soundcard which was a complete hassle to use since it was very loose and would fall out really easily. He spilled beer on it once, which accidental care covered and sent him a "new" replacement (refurb). Then he spilled beer again on it, which Dell once again replaced with another refurb. Now it's nearing the end of his warranty, and he's considering doing it again, except this time, not so accidental.
Third M1530, he went with the 1440 x 900 LED screen (back when LEDs were a premium). This one went swell.
The M1330 had all sorts of problems. 8400M GS overheated like a beezy, he had it replaced twice, before finally giving up on any sort of gaming on it.
In short, Dell isn't quality, but you can't beat their customer service. Dell coupons are crazy too. The M1530s all retail for ~1700-1800 with 3 year warranty, but a couple 25% coupons + a couple other things brought it down to ~$1050 shipped iirc.
Anyway, having said that, I had a really interesting choice to make this year on my refresh. A couple of options to consider, since while I'm not a huge gamer, I do game casually as with most people. My roommate's the hardcore gamer, so while I don't game "hard", I do like to try the newest, most popular games (aka most demanding) that he has lying around. With the old, but still reliable 8600M GT GDDR3, I've been at least able to have a "taste" of what it's like with the newer games. I don't care for absolute flawless gaming experience, I just like to "try" games, but recently, even on low settings, that hasn't really been an option.
Anyway, like you, I'm an engineer (sort of, 4th year CS). Basically, a couple laptos were off limits for me: the strictly gamer notebooks (4 years ago, I would've swooped up the Asus G-series in a jiffy) and the strictly business notebooks (we're way too young for those; plus they're expensive). Obviously a consumer laptop (aka your average windows PC) is going to cost less, which is why I don't understand why people are comparing similarly spec'd "consumer" lines to the likes of the MBP. MBPs are most closely associated to the business line if anything, the Thinkpads, the Elitebooks, the Latitudes, and MBP is really competitive as far as pricing goes versus those. But then again, a MBP isn't a hardcore office notebook either, it's somewhere inbetween the two. So that's something to expect.
And comparing retail prices are retarded and unrealistic. I'm not paying retail if I don't have to. Apple isn't the king of deals, but there's still a student discount + their summer deal, and there's always Amazon. And every PC vendor has tons of coupons.
Anyway, the PC lineup haven't been as quick with updating to Sandy Bridge, and I knew for a fact I wanted SB. And I knew I wanted nothing bigger than what I currently have (15 inch), but nothing as small as my roommate's 13.3 MB. So basically, it was 14 or 15 for me. Portability was a factor, since it was going to be my only computer... everywhere. I couldn't be lugging around an 8 lb Alienware with me everywhere; height of 40mm or so is the upper limits of what I tolerate as "portable". Discrete graphics was also "mandatory", since as aforementioned, while not gaming full-time (impossible with my major anyway), I still like to dabble. I wasn't looking for a hardcore 460m GTX or something, if anything, the power/heat would be a turnoff for me. HD didn't matter to me; I'll be getting my own SATA 6 compatible SSD once prices are competitive and not OCZ chewing up everything in sight, and firmware stabilizes to the point where BSODs aren't at some insane 20% rate or whatever it is. RAM's not a big deal; every vendor offers plenty of configuration there, and it's pretty easy to replace anyway. As for the screen, ideally I'd want 1680 x 1050 like my current XPS, but preferably no lower than 1440 x 900. I don't care for 1080p; I find that unnecessary. As always, build quality and design is important too.
HP is known for poor quality, but their Envy line is still pretty... envious. Not the worst looking laptop. Went to Best Buy to check out the build quality, and wasn't impressed. All show and no go.
Acer is basically your "performance for cheap" brand, and it really goes to show. Plus, it's kind of embarrassing sitting in a class with a bunch of tech-savvy individuals with... an Acer. Cheap bastard.
Asus is the "go-to" mid range gaming notebook imo. However, their N-series model caught my eye. It's got similar specs to a high-end MBP, with a 2.2 quad and 540m GT (equivalent to 6750m); 8gb 1333 RAM to boot. Amazon sells this for under a grand shipped. Apparently it's got best in-class speakers too. Review here:
http://www.notebookcheck.net/Review-Asus-N53SV-Notebook.43709.0.html This one's worth a look.
Next one I was legitimately interested in purchasing was Lenovo's month old (new???) Ideapad Y570/Y470. The Y470 was especially interesting since it was one of the few 14-inchers that got fitted with a quad core (Alienware was the other). The 550m GT in it also fit the bill perfectly, however it's still running on GDDR3, so probably not. There's about a 20% difference between GDDR3 and GDDR5. What a shame. The Y570 though has the more powerful 555m GT, this time with GDDR5. In addition, they seem to have clocked the stock quad core a bit higher, from 2.0 -> 2.1. Build quality was also exceptionally above average for a consumer notebook. But the kicker, at least when I was looking at it, was the pricing. Dealzon had the i7 2630QM, 8GB, 555m GT for $879 (
http://dealzon.com/deals/lenovo-ideapad-y570-coupon)! There's also a "rapid" drive option (which I take it to mean an SSD used as boot partition with a standard HDD for media use, but all in one drive) with a Blu-ray drive for just $120 more; worth it imo. But what kept me from buying was the lackluster resolution; 1366 x 768 just doesn't feel right, especially on a 15 inch. But for that price, that quality, and amazing speakers (tried them at Fry's; was a class above MBP for sure); worth looking into. IBM, like Apple, use to top the charts in terms of laptop reliability too.
As far as Dells go, the XPS 15z looks like a 2008 MBP on the outside, with the specs of a slightly worse high end 2011 15 MBP, or a slightly better low end 2011 15 MBP, for about 85% the price. IMO, it's not worth paying the premium for a "PC". The regular XPS 15 502x or whatever the model is, offers better bang for the buck. It's still in the class of the "high end" consumer PC, with better performance, and not necessarily worse styling, but "different" styling. And you're not paying as big of a premium. Plus, those have a history of huge discounts. With the 15z, it just feels like you're paying for a MBP look alike, with pretty much the price of a MBP... why not just get a MBP? If the high end 15z sells for $1200 though, I'd reconsider it, since it's still technically of "ultra-slim" class.
And of course, talking about quality, stylish PCs, we have the Sony Vaios. Like Apple, we're paying a premium for the brand, for the design, and for... well something intangible that we're being charged that I have no idea what. Their new S series was the only 13-inch I considered getting, since they've somehow managed to fit it with a 1600 x 900 screen... on a 13 inch! 6630m isn't bad of a discrete, not great, but because it's a 13 inch, ultimately it's not coming with quad core. And the pricing is basically a lick away from Apple's behind (that idiom didn't make sense). They've recently updated their E series to SB, but the EB series is the one I want, and that's still on old architecture. Eh. No recommendations here.
MSI's a gaming brand, won't go there. Nor Alienware, or I guess it's called Dell now, but yeah. Or Clevo. Yeah.
And finally, the MBPs. We can use the baseline 13 inch as a starting point for comparison. ~1150 shipped for a 13 inch with basically.... nothing is pretty bad by PC definition, but we'll consider this ground zero of Apple-world. Because it's only going to get worse from here.
The i7 13 inch is $300 more, for a slightly bigger harddrive and a CPU upgrade. The HD upgrade is $40 tops, and the CPU upgrade is ~$150, give or take. Makes you wonder what they're doing with the other $100 eh? Not to mention, the dual core i7 upgrade, at least in my eyes, is pretty worthless. You're getting a ~10% performance boost for 30% more money; but you're digging yourself a whole slew of heat problems. It's a 13 inch MBP! Apple's known for design over function mindset. And my God, Apple REALLY needs to upgrade the display on these things. 1280 x 800 display is so 5 years ago.
The upgrade to the 15 inch is another 300 on top of that. It's a bit harder to quantify pricing here, but I'll try. Technically, the quad core processor costs slightly less than the i7 from the 13 inch MBP, give or take $50. However, given the choice between the two, I'd choose the quad over the "more expensive" faster clocked dual core any day. We'll call it even. Same HDD. Same RAM. 6490m card... how do you put a price on a card that you can't technically buy anywhere? Anyway, I'll give it a shot. Desktop 6450 retails for ~$60, and giving Apple the benefit of the doubt, we'll put notebook card premium at 100%, creating a theoretical, grossly overpriced estimate at $120 (trust me, if a 6490m is available, it would NOT be priced at $120). That leaves $180 for the screen. Yeah... no. Not even close. Apple's reaming us again. Albeit not as bad this time. There are some intangible factors to consider. 15 inch is MORE physical real estate; you can't put a price on that. And while the 6490m isn't great, or even good really, it's still miles above the HD 3000.
And finally, the upgrade to the 2.2 qc with 6750m. With student pricing, the jump is only $300, instead of $400 retail. The ATI 6750m... now that's a real card. I'd put the processor upgrade at ~$120, the graphics upgrade at ~$120, and the HDD upgrade at ~$50. Quantitatively at least, that's a worthy investment imo. And once again, you consider the intangible costs. The processor upgrade won't be a huge help for every day use, at least not at the base clock speed anyway. It's not worth $120 to me. The 6750, on the other hand, is a world of difference from the 6490. That's easily worth more than $120 to me. HDD is eh, since I'll be using an SSD sooner or later. But hey, 750 is still more than 500, and in this day and age, 500 is pretty easy to deplete. It's worth $50. An optibay's like 20$ anyway.
What blows though, is that you would need to let apple ream you twice in the *** before getting your money's worth in "going to the next step".
Anyway, as for me, I settled on the 6490m. While I knew the upgrade to 6750 was "worth the money", as but ultimately a consumer with a finite budget, I also had to take into account the TOTAL cost, and I really couldn't justify spending 2 grand on a notebook that'd last 3 years. 13 inch had horrible resolution so that wasn't an option. I just had to accept the fact that I got knowingly double reamed by Apple because I wanted to "try" their product. I was going to wait for their "summer back to school deal", which was basically a free iPod Touch, which I could sell for ~$170 and make up some of the price difference. That would result in a total cost of ~$1700, not too bad. Too bad that never came. Bummer.
Anyway, finally, a couple days ago, I received an eBay coupon for 10% off tech products (max $100) and I figured hey, why not give that a shot. Ok well this is dragging on too long, but long story short, I ended up winning a NIB (new in box) 2.2QC 6750m GT for 1670 shipped, and $35 ebay credit, for an effective cost of $1635. Not too shabby. Didn't expect to get the high-end, but for almost PC competitive pricing, who am I to complain? If you're an ebay user, you should've received the coupon too, and it's good until 6/26.
Oh, and I've had this Dell laptop undervolted all this time; I'm going to miss that when going to the i7s.