Here are my initial reactions opinions and it's mostly questions based on the limited knowledge I have of the technologies used and then the hypothesized answers I came up with in my head based on the research I've done:
Why didn't they use a higher tier GPU or even go with Nvidia?
Thermals and cost? They've been rocking AMD's jock on the Pro line for a bit now and Polaris is nice, and runs at 14nm which Nvidia hasn't hit yet (Pascal is 16nm, but not sure how much 2nm affects thing). Thermals could be an issue but Nvidia runs cooler on the new 10xx line at least for desktop. Power consumption is another factor, but as this is a Pro level latptop I would have liked to have seen a higher tier card with more VRAM and possibly GDDR5x instead of normal GDDR5. AMD doesn't even have a section on their webpage for the 460 (mac edition):
http://www.amd.com/en-gb/products/graphics/notebook/r9-m200
Ultimately it comes down to how well the software and hardware are integrated to affect performance and Apple is usually king at this. Gaming will not be optimal as on a dedicated gaming latpop but Final Cut, Logic Pro, etc ought to run butter smooth.
Why didn't they go with DDR4?
I can't find good materials over the improvements of LPDDR3 vs LPDDR4. Some here have said lower latency with DDR3 while maintaining same frequency makes DDR3 better. However DDR4 uses less energy which equates to lower heat output, which allows apple to keep thermals down and profiles smaller. I think DDR4 should have been used. I would have liked to have seen a 32GB option here btw. Creative apps love RAM. The more you can throw at them the better. This was a huge misstep by not allowing for a 16x2 DIMM upgrade option (x2 to maintain dual-channel functionality for better performance).
Why didn't they upgrade the iMessage camera to 1080p?
This one baffled me. I mean c'mon. Full HD has become more of a standard for web cams and can be bought relatively cheaply as an external. To keep peripherals to a minimum this thing should have been made into a 1080p cam. Wireless AC can handle full HD streaming.
Price to performance?
How much of an "Apple tax" are we paying? I configured an MBPro with some software like LogicPro, accessory cables, and apple care at over 4700 bucks--this was going with most upgrades except storage at 1TB instead of 2.
I can order The New Razer 14" latptop with an Nvidia GTX1060 with 6GB of GDDR5 and 4k display (not true 4k), 16GB of DDR4 at 2600 bucks. Adobe equivalents of FinalCut and LogicPro (although you get FL Studio for free which is a $199.99 value) added software would jack this up considerably and I noticed no extended warranty option. You can also buy the Razer Core to add an external GPU for more power (then plug into full monitor).
Dell has an XPS laptop that is comparable hardware wise (except GTX960 gpu) but apparently their web design is stuck in 2005 still and this was a bitch to find. It's still cheaper as well. There is also an option for 32GB of RAM.
HP and ASUS offer entirely too many friggin' options to sift through. God these morons need to limit SKUs and improve webdesign.
Conclusion:
Apple's hardware is not 100% up to snuff and I don't think it ever has been. As far as I can remember, their GPU options have never been top-tier or even close to it. There should be more RAM, and the question of ddr4 lingers; and the GPU line-up might not be the best choice. Also configurable options should have been expanded to add more RAM and an even higher tier GPU. But ultimately Apple integrates the hardware they use with the OS and software developed by them and 3rd parties so performance for productivity/creative based applications is stellar. Games may not run the best, but editing film, photos, etc. ought to be.
Price-wise: I do think it's a bit expensive. I'd like to see at least a $500 price drop, but otherwise I think the new version is worth the price of entry. Ultimately, I may go to my local Apple Store and tell them to sell me on the MBPro versus the Razer and see what they say.
I look forward to the reviews and the iFixit tear down. I'd like to see reviews compare the 15" to previous MBPros and what is currently available on the Windows side of things for such things as film editing, and other creative activities. Maybe some gaming too, but I have my custom built PC for gaming.