I have a Thinkpad Edge 13 AMD athlon neo x2/1,5Mhz and IGP ati radeon hd 3200!
The catalyst driver has been absolute crap since the first day i bought the laptop.Video tearing was awfull and 2d performance crap, lately they did introduce this new shinny tear free video feature. Well when i have that feature active my Cpu is on 40-50% usage playing a simple divix or avi file. Oh yeah tearing is gone.As for 720p video those are unplayable with tear-free option enabled, take too much of the cpu and gpu resources i guess. On the good side 1 mmo game i play worked fine with wine.
Now for the opensource drivers for my humble need they provide low cpu usage playing divx files around 9% and i can actually play HD 720p content flawlessly. I have to mention that i use 2.6.39 kernel and lastest mesa from ubuntu xorg ppa.
If i were to buy amd for linux usage i`ll never do it again. Intel sandy bridge graphic performance is very good for laptop usage and with latest kernel and mesa will run like a bliss plus u have video-acceleration! AMD says they try and been saying this for like 4-5 year but the fact is they lack the brains to do it. Where Nvidia managed to always deliver faster more up to date and better drivers!
In my opinion best option would be for laptop on linux go for Intel SB with and i5 proccesor.
As for desktop if u what cheap system: AMD cpu and Nvidia and u call urself a winner
I am using HP635 and it is working very fine. I would like to recommend you this laptop. The good thing about this product is collaboration with linux and window both. Another good point about this is battery back up.