I've been using an X230 as my personal laptop for a while and I
absolutely love it. Comparing it to my work T430, it's smaller, with a vastly better screen (IPS, albeit lower resolution) and on the whole it doesn't make too many compromises versus the T series.
I second the Lenovo service manuals. Behind the excellent Linux support they're the reason I buy Thinkpads. Not only can you completely disassemble them, reading through their service manuals it's almost like Lenovo encourages you to do it. Compared to this, a teardown of the 2013 Macbook Air makes for some pretty depressing reading: soldered RAM, proprietary SSD modules, proprietary screws, etc. I get why people buy the Air and Ultrabooks, but I'm glad the T and X series are still around and still dependable workhorses that you can service yourself with nothing more complicated than a swiss army knife.