Earlier quoted context omitted.
One of my co-workers has the current gen (9550) and Ubuntu 16.04 runs great on it. I think he's got an intel wifi card, I'd just check Linux compatibility with the Killer wifi card before going that route. It's easy enough to change a WiFi card out aftermarket if there is issues though, an Intel 8260 card will run you $30.
Does that include good working power management and a fully functioning touchpad? I went down the XPS13 Sputnik path and had endless disappointment with constant fixes.
My biggest complaint about the XPS15 I had a little over a year ago was the spacebar. There was a manufacturing defect in mine where the touchpad ribbon cable pressed up against the spacebar and was causing unregistered keystrokes. I read internet forums where multiple people had this issue. Maybe Dell has fixed the manufacturing issue by now, but it was bad enough that I returned the XPS15.