Its been around for a while but ive never felt its a serious player.
In terms of free AV's GAV is great, despite the real time protection not been in place as yet.
AntVir's virus detection firgures seem a little low to me, NAV detects about 10,000 more threats that it does (as of 2003-03-15 beta defs NAV detects 63300).
So detection is a little lower than the big antivirus companys.
Its interface is poor to IMO. May be nice to watch the devlopment of this but its already branched out into a commercial edition so the free one may get neglected after time.
It sure does look at least like a low cost alternative.