Use Sophos Enterprise at work - use diddly squat at home. I find it remarkable that on using little other than Windows Firewall on my gaming PC that I never seem to suffer from all the internet and LAN issue than other gamers do.
Just me being cynical, but I think the more crap you put on your PC to stop other crap - the more performance issues you get. Im lucky though - if someone screwed up my gaming PC remotely, the only thing of any consequence that I'd lose would be a few high scores on the PC.
D.