Yup, I've used BitDefender, in fact, I should probably go back.
I think we've gotten to the point where an AV is only as good as its target profile, I.E. if the hackers are targetting it more or less. If less, then it's a better AV. Which is loosely correlated to how popular it is, hence why Norton and McAfee aren't as effective as they used to be -- because they're the most popular.
And if not, at least it's a major factor.