I've been trying out FreeBSD 11-BETA1 on my Thinkpad X1 Carbon (1st gen) IvyBridge, and it seems to work pretty well. I have power management and suspend (unless I load tpm.ko), the wifi all works and accelerated graphics seem pretty good.
I've looked at the X1's before and heard good things about them and considered purchasing one. I'm a little hesitant to purchase a laptop without having seen or touched it myself, though. A cow-orker recently got one and, after playing with it for a bit, I quite liked it.
Anyone else here have an idea what the "current" generation of the X1 is, if the hardware is very different from your Gen 1, and/or how well-supported a new X1 would be under the latest -RELEASE or 11-BETA/RC (I'm not opposed to running -CURRENT but usually avoid it on all but dev/test machines)?