The latest update to AVG 6 includes some sort of "micro update" system, so that subsequent updates **from control centre on schedule or update now** should be smaller.
NB. Doe to the reduction of the FREE version to a single update server, and current demand levels, getting AVG to update can be pretty slow... try again, or preferably try at other times until you succeed. And if you do use the auto-update, avoid obvious times like on the hour and 15 mins etc.
No idea how much longer the free version will be updated for, and it does NOT score terribly well on tests - but then, you also get people saying "it found one that XXXX missed"
Just reminded me....
http://www.command.co.uk/html/offers/
Read the right mag (or perhaps even if you don't - naughty!) and you seem to be able to get a regular 1 year offer on this one - It uses the F-Prot engine, I believe