If you post a negative review of a plugin, you'll probably never see that review again. They just don't post it. And if you ever need a refund for a bad plugin, too bad, you won't get it. The plugins on CodeCanyon may seem like a good deal, but when only 1 out of 3 ends up being usable, you wind up spending more money than you would have buying from reputable sources that have fair money-back guarantees.