My overall favorite was the x230, whereas the x240 was unusable due to an erratic touch pad (the cursor would jump around while typing code).
Nowadays I use an X1 at home and a MacBook (M1) at work, and the Mac wins regarding weight, speed, interoperability (WiFi, sound), battery and raw computer power, but the x1 wins with respect to keyboard, Linux support. I think the MacBook makes the better travel companion but the x1 makes the better dev machine (Linux is a "less odd" UNIX than MacOS X, speaking of paths, command names etc. memorized from varies Unices over the years). I would be keen to try out the X1 Nano, but the 1st generation is too similar to my existing box to consider an upgrade.
BTW, whatever happened to the "ThinkPad Classic"?