The t480 was the last thinkpad with a useable CPU and a rich feature set (dual battery, removable battery, replaceable ram, ability to use a 2nd SSD via the wan slot). Linux support is great and libreboot support was just released for it.

I also have a newer amd x13 thinkpad. Sure the overall performance is better but the keyboard is not as good, s3 sleep battery drain sucks, and it takes forever to boot up