I had a T510 which was great ( heavy but great) , I liked the keyboard , and the graphics card was good enough to play games. Optical drive , good wireless, limited by power ( only got like 2 hours at best) . Linux support was also good. Performance was good. I had a dual scren dock , and the device could drive both via DVI.
Then I lost the 5 key and IT issued me a X240.. Lighter, newer, small screen, nice and snappy, no optical drive, much better battery life. I feel cramped on the screen. There are screen options. 1366 X 768 , 1366 X 768 touchscreen, and a larger one 1920 x 1080 all 12.5 inches. I have the 1366X768 non touchscreen and I feel cramped.
I have a dock for this x240.. but the laptop can't drive both screens with DVI.. One has to be VGA. I dunno if that's a limitation of the particular dock that I got, or if that's a limitation of the video card, but after going Digital I can't stand VGA. Too fuzzy.
So the keyboard. I have had some trouble getting my head/hands around this new keyboard. For one f1 f2 f3 function keys don't "work" out of the box . They all do their "special purpose" like volume , display changing , mute etc. I had to tell it : by default when I press the F1 key .. it send an F1!
Also I can't get "end" to work without also pressing "Fn" . ... Which I now call the "effin" key if you know what I mean.
David