We use these XPSes and the current MBPs here. I do not recommend the QHD screens on a 13", if you ever flip Linux to text mode it is just about unreadable, and I think only MacOS handles HiDPI elegantly. Ubuntu needs a lot of tweaks to be usable.
I also agree that the trackpads are very poor, and that's still one of Apple's main strengths. Although quite why the trackpad needs to be quite so enormous on the current models is a mystery to me, so many people catch it when typing.
I just tried this on an Ubuntu machine and sun12x22 doesn't exist. After some poking around and reading the linked wiki page, I found that Lat2-VGA32x16 (case-sensitive) produced a readable display. Given that running `setfont` on its own errors with `Cannot find default font`, I wonder if the default Ubuntu install neglects some things.
I actually prefer QHD screen since it looks great with 2x scaling (and I don't really care about text mode which is only useful for recovery). I have no problems with HiDPI or touchpad after upgrading from the ancient 16.04 LTS that comes preinstalled. I hope that the next edition would come with 18.04 LTS which should offer a much better user experience out of the box.
I've tried the alpha on a Acer Surface-esque tablet with a HiDPI screen and agree 18.04 is much, much better out of the box - scaling was set sensibly and usably on first boot. Very much looking forward to the release.
I also agree that the trackpads are very poor, and that's still one of Apple's main strengths. Although quite why the trackpad needs to be quite so enormous on the current models is a mystery to me, so many people catch it when typing.