The new XPS 13. It's fine. My disappointment is 98% software. The XPS has poor camera placement (but you know that going in), the buying experience is awful (here in Asia anyways). I see myself sticking with Linux, but no loyalty to hardware vendors. I'm hoping the MateBook or Chromebook become [relatively] cheap and powerful first class linux options.

Install Xubuntu on XPS, and set up i3 as your window manager - this is my current setup and I love it. Takes a bit to get used to a tiling window manager, but once you get it it's amazing - I never understood why people value overlapping windows anyway.

I like UIs that feel premium. Needless to say, Xubuntu and i3 do not make the cut. Left with Gnome 3 (ugh) or KDE (options galore). All other DEs feel clunky (graphical glitches, sub-par design) and are also usually buggy (which is normal for an open source project with such a big scope).

XFCE looks a lot better with a different window theme installed, the defaults are absolutely terrible. There's as many options for XFCE as KDE, but it definitely takes tweaking before it looks good.

i3 is generally used for its productivity benefits, not for appearance. You can still spruce it up with a new bar (see Lemonbar or Polybar), but overall people choose it because it feels nice to use. The people on /r/unixporn have done a pretty good job of making it look good though.

Try Budgie. It's the DE developed for Solus and it's great.

I have an older XPS 13, the touchpad is bad on Linux only. Have you noticed that issue?

I recommend Lenovo T480 for Linux. Supports 32GB ram as well.