Lately I've been using Kubuntu, running on an IBM ThinkPad R51. Straight out of the box, everything works. Wifi, sound, docking station, USB drives, the works.
Its only got a 1.6Ghz Pentium M, and 500 meg of RAM, and it chugs every so often. Probably could do with about a gig or RAM, CPU is probably enough.
I'm running the Beryl window manager, which gives you some pretty naff visual effects, but they get a little annoying after a while, and I”m probably going to turn them off.
Evolution works well, and it connects well to our Exchange server, and even better, because Evolution uses the OWA URI for access, I can even access the server remotely without a VPN. Thats very nice. Although, I cant connect to more than one exchange server, so I'm unable to connect to the local customer's server at the same time. That's a downer.
This morning was the real test I thought. I was emailed a couple large images embedded into a Word document. It was a snap. Evolution fired up OpenOffice, and I had it printed out in no time.