I've gone through a couple X1 Carbons. The first one (2012) had a fan failure, but I got a replacement cooler on ebay for $20 and it was easy enough to replace.

I've gone through a couple X1 Carbons. The first one (2012) had a fan failure, but I got a replacement cooler on ebay for $20 and it was easy enough to replace. Eventually it died when a drink spilled on it. The second one (2014) had awful soft-touch function keys. They were so bad that the softkey to change the F-number to brightness/volume sometimes didn't work, so I'd get stuck in one mode or the other. Eventually, the down-arrow and Delete keys stopped working. It also had the mouse buttons integrated into the trackpad, which was terrible. I love the form factor otherwise. Thankfully they've moved away from the softkeys and integrated mouse buttons, so I'm comfortable recommending it again.