Which Dell XPS runs Linux better? XPS 13 or XPS 15?

I recently purchased both a used XPS 15 and a new XPS 13 for roughly the same price. My primary goal is to "learn" Linux on it by using that as a primary OS while having a dual booted Windows 7/10 "backup" OS in case I need it (or my wife wants to use the laptop).

I have: XPS 15 9550 i5 (6th gen) 8gb ram 25gb SSD 4k touch screen

XPS 13 9360 i5 (7th gen) 8gb ram 256gb SSD 1080p non touch screen.

I want to keep one or the other. Portability isn't a problem I don't mind carrying either laptop but I want it to be functional with linux.