I have an XPS 13 and run Linux on it. The drivers for the touchpad were very rough with the version of Ubuntu it shipped with, but updating to a Kernel version > 4 fixed all my problems.
1) the touchpad never worked;
2) the keyboard still has problems;
3) some of the more important programs look just horrible on Linux, as the resolution is just too high;
4) sometimes WiFi just does not work;
Is that with the 'Infinity' screen or whatever they called it? I just got the 1080p one and don't use scaling. I had a Yoga with a hidpi screen and agree that a bunch of programs just don't work at all with scaling in Linux.
It's sad to see you had trouble. With the latest version of it (9350), I had trouble at the beginning but upgrading the kernel to 4.4 solved all of them.
Also, regarding #3, I've heard Linux Mint as great HiDPI support in their last version.
I've had similar experience with my ASUS N76V: it worked fine for a number of recent releases, but only with the upgrade to Ubuntu 15.10 did the touchpad start working decently (I couldn't turn on two-finger scroll before, because that resulted in phantom multi-finger gestures).
Support was terrible last May when I bought the laptop. Now everything works except the hidpi issues. But that's not laptop problem.
Overall the only problems I face is with
- GTK2 apps, they look awkward. Eg. very small icons
- Spotify, Steam, Skype will look very small
However the biggest turnoff is that whenever I connect to external display (1080p), I have to apply a weird command with scaling and panning options. This results in blurred look, a bit lag and fan spinning hard. I wish there was some option to do selective font scaling based the screen.
1) the touchpad never worked; 2) the keyboard still has problems; 3) some of the more important programs look just horrible on Linux, as the resolution is just too high; 4) sometimes WiFi just does not work;
...so much for the Sputnik project.