It depends what you want in a laptop. I'd say the T480 is a great option because it's the last in the line without soldered RAM and has a fair amount of upgradability.
That said the T440P can do most of the same stuff but it's a little less powerful. Though I think you can upgrade the CPU to a degree.
There's other things as well like if you want to install Libreboot or sometimes people will sell the laptop and the dock together.