i have the Radeon HD4670 and is a good deal considering the small price difference. It handles games amazingly well like COD4,5,6, mass effect 2 and much more. The only thing to look out for is the enlarged mouse cursor with windows 7. It is very annoying but there is a solution like the BIOS trick and the new v10.2 hotfix catalyst.
so do yourself a favor and search "Huge mouse cursor windows 7" on the internet. and then make a decision on the purchase.