1. New keyboard is painful to type on. I use it 99% of the time with external trackpad / keyboard / monitors but that other 1% pisses me off.
2. Battery life is mediocre. I don't keep track but I'm always surprised how quickly it goes when I'm unplugged. How about stop trying to make them thinner?
3. The touchbar is f*cking horrible. It's a bad solution to a nonexistent problem. My fingers touch it by mistake often, finding ESC is awful, and worst of all, it sleeps! Give me back my ESC and media keys.
4. A computer with two GPUs SHOULD NOT CRASH when plugging in external monitors. It should also wake from sleep properly in clamshell mode. A lot of the time I actually have to unplug one monitor to get either to turn on.
5. Support for external retina monitors is terrible. I spent the better part of a day getting two Dells to be readable / look good.
6. Xcode. A medium sized project compiling now hits all 8 cores so hard music will actually stop playing (I use Roon with a pretty heavy CPU load).
Unless things turn around, this will definitely be my last MBP, maybe leaving the dev ecosystem altogether.