I'm also a false positive hunter.So... is too stupid question when i ask you "Why you use it" ???
BitDefender has more false positives than any other single engine AV, so I don't recommend it.I would use Avast, Bitdefender has thousands of false positives.
+1If they absolutely don't know anything ("Hey, what's quarantine? What's scanning? What's definitions?") then Bitdefender without a doubt. If they know basic settings and to tell the difference between false positives than Avast!. I'll have to vote Bitdefender here, but Avast! is a much greater antivirus with those with basic security knowledge.
Update: See below post. I know longer reccommend Bitdefender. +1 to Avast!
There are 2 options for hardened mode.Avast + hardened mode for newbies