The drop for older hardware can be a problem for some people. My laptop has a HD 4250 that's intergrated and a HD 5470 that's discrete. So can I install the Catalyst 14.3 beta? Nope, at least according to the drivers. I imagine it wouldn't be any different in Windows either. So for now I use open source drivers, cause they actually work.
That HD 4250 chipset was used for sometime. There are people with discrete HD 6000 and 7000 cards that use a intergrated HD 4000 for low power savings.