I hit 1-5k (down from 1-80) with them a few months ago. That combined with rubber cheques meant I moved on. Not just oversturation - I think the stats system is totally fucked and just does that to some accounts.
Only other horror story I ever had was Ezgreen which again was more lack of payment than bad stats.
As for good probably
Big Players has been the best so far that I've tried recently. Probably because join price isn't stupidly high like many sites.