I have the Dell Precision M5520 developer edition which is the Linux version of the XPS 15 with Intel WiFi and I opted for only integrated graphics to avoid graphics drivers on Linux.
It works flawlessly with Ubuntu 17.10. I have the UHD screen which looks great with 2x scaling. I do a lot of work with Docker and can work much faster on Linux than before when I was on a MBP and had to run a VM.