The Dell XPS 15 9550 is a great notebook, especially if you are planning to use it on Linux. We've tested Arch Linux on the current model (Intel Skylake i7 6700HQ, 4k UHD display, 512GB NVME) for a couple of days now.
Installing Arch Linux on the new DELL XPS 15 9550 can be quite troublesome, here are some tips for the installation. This tutorial covers the UHD / 4k screen model with the Intel Core i7 6700HQ and the Samsung NVME SSD. If you have another model you have to adjust your hard disk path (probably /dev/...