This:
Not all of us can afford the 15" Pro and the Air is underpowered for some of our needs.
and most of this:
I'm a developer and a desktop guy at heart. I have a base 13" MBP (2011) with a 120 GB SSD and 8 GB of RAM which serves as my portable workstation (for those times when I absolutely can't use my own desktop).
I choose it over the Air because:
You're kidding, right? 4 GB of RAM? No Ethernet port? ULV processor? I'm just shuddering at the thought of running a major compile on the road and then having to upload it via Wifi. The Air serves a purpose--it just isn't my purpose. I know I'm not alone in this. Oh, and when I was purchasing, the current Sandy Bridge Air consisted of a whole lot of speculation and little else.
I chose it over the 15" Pro because:
I don't see the sense in spending $2200 on something that's going to sit in a closet most of the time. The 15" model is closer to a desktop alternative (not replacement--no such thing), and I neither need nor want that. And frankly, the 13" model is easier to use while traveling (in flight, at a restaurant, etc).
Side note:
I don't understand all the whining about the 1280x800 screen resolution--but then, I stare at text all day. Since OS X doesn't scale the interface (and fonts, accordingly), I'm more concerned about physical screen size than resolution. In any event, 113 PPI isn't bad (it's actually still better than most desktop monitors).
and add in:
Different people have different needs, as well as different budgets or perceptions of what they're willing to pay for.
I'm in the second case from above, but also agree with the first one - I write software, run VMs, and generally use it as a portable workstation. I'm in 100% agreement with akhbhaat about his reasons for 'why not an Air?' One day I might be using it to console into some older servers via direct connection, the next running a pair of VMs plus Eclipse, various servers running locally at different times, a ton of open browser tabs, reading, reviewing, or writing design or API docs, diagrams, etc., and I work on multiple projects, all of which adds up to a fairly large amount of storage and CPU power. It's also dual purpose for my personal projects, plus general stuff like music, etc., so - yet more storage. It's all backed up to a NAS, but that doesn't mean I don't keep a lot on the local disk. For *me*, the Air is a neat 'toy,' like an iPad with a keyboard instead of touch screen, but isn't enough RAM nor storage for me.
I would expect professional videographers and similar to run into similar issues - most video and image editing software tends to like both cpu power and RAM, while the data sets tend to get pretty large, quickly. Someone may be able to use it in 'mostly desktop mode' with external storage for things like video and image work, but they're still limited the minute they unplug, plus the CPU and storage may not cut it.
Someone else who does mostly text docs, powerpoint/presentations, spreadsheets, browser, general business software, would likely be a great fit for the Air as long as it met their storage needs. A lot of students in most fields would get on well with the Air, depending on discipline. Casual users would love the Air - it's fast enough for most things (and then some), is more than enough for web, email, flash, watching videos, etc.
The 13" MBP is somewhat of a 'tweener' - it's in between the casual or non power user but very light and cool Air, and the 'real' start of the Pro lineup, IMO. Cpu-wise, it's in the middle, while RAM and HD are equivalent (or can easily be made so). The resolution and lack of discrete graphics are the only real downside.
I also agree mostly with akhbhaat on the other comments made, but the 13" MBP low res drives me insane when not attached to an external monitor. It's ok for quick scripting in vi, but going to the widescreen layouts lost us space in the wrong direction - vertically. The annoyance factor when browsing API documentation or even normal web pages or through code with the lack of vertical resolution annoys me. I did use a 13" MB as my primary system for 4 years, and it was great when traveling, and when hooked up to an external LCD, but not, for me, for serious work using only the laptop screen. I do agree the pricing on 'the next jump up' to the 15" is pretty annoying. For me, the 13" is a great travel/portable size, and if it got a screen resolution bump, I'd probably be typing on a 13" MBP instead of the quad core 15" monster I'm on at the moment.
Anyway, it's about different uses and needs, as well as desires, from different people. The Air is great if it fits your needs, and the 13" Pro is better for some, not for others. I'd love to see the 13" MBP screen res jump up, offer the Air and 13" MBP at $999, a 15" starting at $1399, but as it is pick the Air if you're more about portability with some sacrifices that *may* not bother you at all, or the 13" Pro if you simply need 'more' in CPU, storage, or RAM.
