I bought an XPS15 and I put Linux on it. But I didn't buy the "developer's edition" because I still wanted a Windows install, that pretty much just sees gaming. So I don't show in the statistics for Dell as an obvious Linux user, but if my research had turned up that the XPS15 worked poorly in Linux, I would never have bought it.

Almost all Linux users are familiar with the process of putting Linux on a machine, since that's the only way to get it. The thing that's primarily helpful about seeing a manufacturer have a "blessed" linux system to me is more that I can be confident all the drivers I need exist; I'd probably whack the install they sent me and replace it with something else anyhow.