AVG isn't bad, pretty good detections, about the same as most other AV's, including MSE.
People sometimes blame the AV for letting one through, and change to something with a better reputation. This usually makes little difference; almost all of them will let one through, on the wrong day. So what MSE might block on one day (and AVG, or Avast, or Norton fail to block) the others might block on another day, a different variant, and AVG (say) lets through.
If you're otherwise happy with MSE, and it doesn't slow the 'pooter down like AVG does (it has that reputation with a lot of users) I'd stick with it.
Or try Avast.
