According to most AV reviews I have read (including CNET), MSE is dead last in effectiveness. As for Avast, I installed it when AVG 2013 refused to install. Haven't looked back since. I am not understanding "bloats and adverts". There are one or two signature updates a day. I see no "adverts". As for "bloat", I see by Task Manager Avast is using only 7 MB of memory. It has caught several viruses, including some real nasty ones. I really like the "boot scan" part. I had not had an AV program with that. The first time I ran it it found 3 Trojans. I think Avast is a good choice. Above AVG in reliability. I use it in conjunction with Threatfire. Seems to be a good harmony. Just my opinion.