My company was considering using these as our Linux option, but we couldn't enable full-disk encryption (Grub has an issue with encrypted NVME drives.) When I contacted Dell they said Linux was not supported via email, but rather through the community. (I'm now running a Thinkpad that's a few years old and it works much better than the XPS 13.)
X230 Tablet. The stylus works out of the box with Ubuntu 14.04.
Only nit is that the standby battery life is only a few days. I upgraded from the 3-cell (which was pretty old and lasted about two hours) to a 6-cell. I'm still testing it but it lasts at least 5 hours under moderate usage. I think with the brightness on low it could last 10.