Just a quick comment on this and you guys can tell me if my points are valid.
For everyone saying they've used Avast for 5 or 10 years and not been infected, great, but is it possible you haven't been infected because your using other security software, or you practice safe surfing, or your a informed user and practice other safety measures such as updating vulnerable software?
Is Avast a great antivirus, no doubt, is it the best, doubtful, is it right for everyone, unlikely.
So when you comment that you have used it for X amount of years and haven't been infected your really commenting for yourself only, other people have different needs because they use their computer differently, so Avast may not be right for them. It doesn't matter how safe you have been with Avast, they could use Avast and be infected in 10 minutes. So yes, its ok to say Avast has protected you but don't infer it will do the same for everyone with the same rate of success.
Am I out to lunch here?