So I've been using Avast Free Antivirus for 1-2 years now ...so far I think it's good, but not sure if they detect all kinds of virus and malware, but I like the fact that it has file shields, web shields and that browser plugin where they show the safety of the website i.e green means safe, yellow not-so, and red is dangerous, and other features of the antivirus is pretty good for a free version although I'm not sure how effective it is anyway.

But lately, I've noticed that my browser has been slow. Not the loading speed of websites, but the sluggishness and lagging of the browser itself when loading web pages, especially at websites where there are a lot of videos like GameSpot or other game review sites where there are a lot of pictures and videos. The browser would sometimes not respond for 5-10 seconds when I'm loading these pages. So I removed all add-ons because I thought one of it was the cause of the problem, then I disabled the Avast Online Plugin, and my experience improved. No more non-responding browser. Quite smooth when loading those webpages which I mentioned. So the cause was actually this plugin which showed the safety of the website. It had been a useful feature to see if a website if safe, but too troublesome because it often get my browser stuck.

I'm wondering whether to continue using Avast or not. Sometimes I think it's not too strict in detecting virus. For example I googled about the safety of this certain program, other antivirus detected it as a trojan, but my antivirus didn't alert me of anything. I prefer an antivirus which is more strict.

All of the functionality can be replicate by browser extension or addons, such as Web of Trust, Adblock Plus, DoNotTrackMe, Disconnect etc. which take less resources than most of AV online plugin.

To me some of them are just bloatware. Especially the so-called safe search toolbar, and couple other plugins that always come with free anti-virus.

Sometime it is pretty unethical when they trick the users into opting in or installing those optional component without user's consent. But that's entirely different topic.

For free AV with complete protection, no one does better than Comodo Anti-Virus. Though make sure to deselect all of the addons first (selected by default) since they're not that useful.

You want somethin not strict in detecting virus but need something more strict to detect virus...what do you want?