I run various distros on my first-gen X1 Carbon and it's awesome. Everything just works. You don't even have to go driver hunting as you do with Windows. The most I had to do was add a kernel parameter to the bootloader to get the brightness keys to work with more granularity. I would highly recommend going native if your workflow allows it.
Been trying to do this with ubuntu on a desktop, but couldn't get a juniper VPN with remote desktop working. I couldn't get the cert installed to log in through the web interface.
I'll give it another shot.
I have a 2nd gen. X1, (the one without the dedicated function keys) and run Arch on it. It's my Dev and play machine, no problems whatsoever and the 2560x1440 screen is addicting. Can't imagine going back to something with less DPI.