Linux or Windows version? I have not used it for a couple of years, so things
could have changed, but this was my previous experience with it. F-Prot provides
good basic functions. It is not as polished as some in terms of interface.
Windows users are used to more polished anti-virus programmes and Linux users
don't care as much about the interface as long as it gets the job done, which it
did.

I use AVG on my Windows boxes and Clam on Linux. AVG works great and so does
Clam except I can't get it to check automatically since I can't configure dazuko
for the life of me. Clamwin does not automatically scan either, so while it is
FOSS it is rather useless, IMO.

I found this link useful: http://www.freebyte.com/antivirus/#scanners

Good luck in choosing the best one for you.