I'm mucking around with an XPS13 that I've installed 18.04 on and it pretty much works apart from a couple of really annoying things.
The most annoying is that the dual monitor support is really spotty.
I have managed to get it working pretty well with Wayland with the laptop at 200% and the monitor at 100% (both 4K resolution devices) but with X11 I can only run them both at the same resolution regardless of what is set in the device tab.
Until recently, it was working pretty well when I just plugged in the dock, but recently I have had to reboot the machine for it to not have a totally black screen when I plug in the USBC connector.
Wayland is fine for most things, but there are a few applications that don't play nicely.
Has anyone else seen this? Is there a way to make the monitors different resolutions under X?