I've used it some, it seems to be decent. It's alright.
But why buy it, the trial version doesn't really expire. Maybe the active protection does, but that just slows down the system and eats resources anyways, better disable the active protection, and then do manual scanning which afaik, will still be possible even after it expire if it does that.
I have used it and could considering using it again, but I would never to pay for it.