<< A series - All in one, larger, bigger, heavier.
T series - More portable, two spindle.
I think the T or R series are the best. >>
Pretty much got it. A-Series is the Desktop Replacement model. IBM went all-out for performance, so the A-Series sacrifices a little in size and weight to acheive gains in screen size and performance. The T-Series is IBM's "compromise" model, it's not a highly mobile model like the X-Series, and it's not a Desktop Replacement like the A-Series. If you can put up with the extra weight, I would recommend the A-Series, it has some nice extra features that the T-Series doesn't. I could not possibly be more happy with my ThinkPad A21p. I've played around with Dells and my experience has been very bad. I am far from impressed with the build quality of the Dell I have used (Inspiron 8100), and I have heard too many stories about Very Bad Things happening with Dell's laptop mainboards. IBM also has the best tech support I've ever experienced. My average hold time is under 10 minutes and I have yet to encounter an IBM tech who was not helpful.
ZV