I have a T420s. Actually I have two because I bought a second as a spare in case my first one dies. Pros: * matte screen * aftermarket upgrade to 16 GB ram

I have a T420s. Actually I have two because I bought a second as a spare in case my first one dies. Pros: * matte screen * aftermarket upgrade to 16 GB ram * aftermarket upgrade to 2 SSDs, one in the normal SATA6 connection and another in the ultrabay with a caddy, so I can always remove it and put the cd/dvd driveback in if required. * still have a spare PCIe slot so I could add another SSD there or use that instead of getting a caddy for ultrabay The biggest draw for me: power, ethernet, VGA, 2x USB and mini display port are all on the back of the machine so the cables stay out of the way when it is on a desk connected to external monitors. If I am using the keyboard on the laptop then I can have my paper notebook on the right and it isn't in a tangle of wires, or a wireless mouse and mousepad. CONS: * 1600x900, but I use external monitors 95% of the time * the first T420s had some battery firmware issue so it wouldn't hibernate when the battery got low, it would just turn off. Doesn't seem to happen any more and the problem was only with one of three suppliers of batteries so not everyone had that problem