I bought the new 2018 Dell XPS 15 the day they were released. I knew the Linux support wasn't perfect on day 1 but fully expect the rough edges (mostly around switching between integrated graphics and GPU, as you say) to be solved in a month or two.

I had the same experience with my 2015 Dell XPS 13... a few annoying quirks for the first month (mainly trackpad) which the combined efforts of Dell and the community quickly solved. Since then it has been rock solid. I used it for 3.5 years and only upgraded to the new XPS15 to get more RAM.

> So much depends on fiddling, experimenting, and reading.

How about not stressing about it now? My approach this time round is to not spend my own time fiddling with it. I'm going to wait patiently for others to figure it all out and get their fixes into upstream distribution. As my main problem is with GPU switching, I've got plenty of non-GPU projects to do in the meantime...

P.S. If you do want gpu switching on the XPS15, check out this repo:

https://github.com/matthieugras/Prime-Ubuntu-18.04