Thinkpad build quality is definitely on a slow decline. There's a lot more plastic casework in a new model than in a T440, say. They don't feel completely rigid in hand any more. And that's before the loss of a removable, upgradeable battery and the advent of soldered RAM.

A second hand T-series is still what I'd default to if I need a laptop for now (especially for the keyboard), but I'm aware that this is likely not going to forever remain the obvious choice it used to be.