Can't speak for Linux but on Windows the killer wifi card in my XPS 13 gave me nothing but grief. Internet connectivity problems, issues bringing laptop out of sleep, etc. Just a huge headache. Dell would never acknowledge the problem or provide anything but worthless scripted help involving running diagnostic tools even though I told them flat out to please replace the WiFi card. I eventually caved and bought an Intel WiFi card. While removing the killer card, killer's antenna connection ball broke off and got stuck inside the connector socket. I had to use a needle and magnifying glass to get it out. After installing the Intel WiFi card, ALL of the problems went away. Best $20 I ever spent.

It always amazes me when "premium" laptops use the same penny-pinching techniques as lower tier ones. I'm already paying $1000+, where the heck is it going if not quality parts??