T510 or W510?

I want to replace my ancient T42 - am looking at T510 and W510 - and have a few questions.



Screen resolution. Specs on site are cryptic - does HD mean 1600x900 and FHD 1920x1080? What's HD+? HD resolution, but better panel? My T42 has 14" 1400x1050 screen, wouldn't 1600x900 in 15" form seem like a downgrade (bigger pixels, loss of vertical resolution)?



Keyboard. Are there any problems with keyboards on these models? I love the keyboard on my T42, but have heard about keyboard flex on some Lenovo models - that would drive me nuts.



Any reason to pick T510 or W510?



Thanks!

Tom