AVG doesn't seem to clean up after itself so over a period of time its virtual memory use gets pretty high. A corollary is that about that time it presents a big popup announcing that a reboot is necessary (presumably due to an update), and won't take 'no' for an answer (although it allows delays up to 24 hours). I hate rebooting b/c I invariably have several things on-going.

I ran Kaspersky on a small home net for several years b/c it was the only internal product Wingate offered. Individuals' machines ran AVG. I think Kaspersky reported exactly one virus over the period, while AVG regularly churned out warnings albeit sometimes of minor significance. Then there's the issue of the nice Russians messing with their competition...