I got the 1st gen Lenovo ThinkPad X1 Carbon, and it didn't hold up great. The balance of weight, power, battery life, and Linux support were huge for a traveling programmer. By the end of year 2, though, I had replaced a broken screen, and the battery life was down to 30-60 minutes (from about 6 hours).
I decided to give them another chance on the 4th gen X1 Carbon, and I've been very happy so far. The build quality seems much better, and they've nixed some of the annoying "innovations" from the 1st gen one (ironically including a touch bar at the top; they reverted to normal keys). That said, I've only had this one for about 5 months, so I might change my mind by the time another year or 2 passes.
I decided to give them another chance on the 4th gen X1 Carbon, and I've been very happy so far. The build quality seems much better, and they've nixed some of the annoying "innovations" from the 1st gen one (ironically including a touch bar at the top; they reverted to normal keys). That said, I've only had this one for about 5 months, so I might change my mind by the time another year or 2 passes.