Ubuntu 16.04: Pretty much works flawlessly as long as you have Intel WiFi- I had some issues with a flashing screen at first but they all seem to have been resolved using `apt-get upgrade`. Suspend/resume, audio controls, and brightness controls all work fine. I run docker images for pretty much everything and it's great to have native docker without a VM involved.
Physical Characteristics: It is very light and easy to use on the lap, on the couch, or in bed. It feels more like a MacBook Air than a MacBook Pro. Fans are on the bottom but they don't really spin up that much, even when I don't have anything under it.
Keyboard and Touchpad: Keyboard is fine. Touchpad is a lot smaller and more "clicky" than a MacBook Pro. The force touch on the MacBook Pro is way better (it's pretty much the gold standard of touchpads).
Screen: I have the FHD screen because I don't care about touch, and it is Matte (the QHD+ touchscreen is glossy). DPI scaling in Ubuntu 16.04 is hit or miss. In my experience, some apps, like Chrome, only respect DPI Scaling if it's in multiples of 0.5 Other apps, like Firefox only respect DPI scaling if it's an even number. JetBrains products do a good job of respecting DPI scaling though. I keep it at 1x DPI scaling, so everything looks pretty small at 1920x1080. If you go with the QHD+ touchscreen, native resolution is 3200x1800 so 2x DPI scaling will be an effective resolution of 1600x900, and it will look great. I think most apps should work fine at 2x DPI scaling.
Webcam: The webcam location really is stupid. I dislike video chatting on this computer so much I'd rather use my phone. I use Android and kind of miss iMessage and FaceTime from the mac (it's how I would talk to some Apple friends), but whatever.
Other Thoughts: Linux FTW. IMO, the last good release of OS X was 10.6.8. Everything after that either changed the scrolling direction or added some sort of bloat to the OS. I'd run 10.6.8 still if I could. Ubuntu 16.04 feels like getting your life back. It's super quick, you can use apt-get to install dev tools instead of hacking around with homebrew, you get the real version of `sed`, and you don't feel like Apple controls your life anymore. Gotta say it twice- native Docker support and no messing around with VMs anymore!
Take the leap of faith and get the XPS 13. Or a Lenovo with good linux support. Part of me wants to try out the big ass trackpad on the new MacBook Pro but none of me wants to go back to paying $2k every time I want to upgrade my laptop.