Yeah i've had issues with my XPS 15 9550 as well. I guess they have not been sorted in 9560 :( Once I customized everything (replace wifi card with an Intel based on, new battery under warranty, many many many BIOS fixes) it works well.

However, I would probably steer people to the Precision 5520 instead if you are going 15" and Dell. Comes with Linux and is business class which hopefully means less stupid QA issues and better tech support