There is a new model coming out soon, so you might get a discount on old stock.
I've been using the Dell XPS range since 2012. I've had 2 Dell XPS-15, and last years Dell XPS-13(the newer one is even better).
I only use Ubuntu, so i just replace Windows(eventually, might keep it around on dualboot for 6 months or until the next Ubuntu release). It's a breeze to use. The only time i've had problems has been the shutdown/suspend sometimes get stuck. Other than that i've not had any issues. The hardware like wifi, graphics all worked without me doing anything.