Well I've just gone back to Avast 7 after trialling 8 for the last couple of weeks. My computer slowed down considerably with 8 installed. Was not impressed. Avast always had the edge for me because it was generally less obtrusive, lighter and faster than the competition, but it seems the latest version has now gone full retard and has become just another piece of bloatware. And what is with that GUI, yuk! The majority consensus seems to be that Windows 8 has a terrible GUI, why imitate it? It is only going to go the same way as Vista.
I'll be sticking with 7 for the foreseeable future thanks.