I haven't gotten any rakeback for quite some time from PP. No interesting bonus offers either. It depends on your winrate. I'm 7,5bb/100 over the last 7000 hands and 5NL I'm not so sure how representative that is, or how many hours of play that includes. I'm only running the PokerTracker trial right now, and I'm still a little confused with the interface, but if I get this right, I paid about 500$ in rake, so rakeback would have been awesome anyway. But who knows. Maybe the rakeback sites are less fishy. (It's possible that it counts the rake for sng's too which is humongous at PP, and I still play with a profit at the end of the day - but a marginal one compared to cash games, so I stick to cash games most of the time)
The good thing is that you can be a break-even player and still make money with rakeback I guess.