[Glyptodon]

My Boss picked up an Ubuntu Dell Precision 15 5000 and though it's a beautiful machine ("4k" or "retina" screen, metal, etc.), it turned out to be a bit buggy/odd with the version of Ubuntu that it came installed with. May be nVidia Optimus related and the fact that it came with 14.04.x rather than a newer version of Ubuntu, not sure.

And among other things Dell installs a special custom package to prevent the super key from working at all, which was/is very odd and was a bit of a hassle to reverse because not only do you have to uninstall their super key disable package, but you have to install a tool to configure Compiz to re-enable it once the package is gone.

I'm guessing (but don't know) you get a better experience with the XPS 13"?

Not sure if it's an unusual case or not.