I got the $22 one for the same reason you signed up, late fees. I don't know if its the area I live in, which is a medium size town in Michigan, but it seems to only take them about 2-3 days to get them back, and another 2-3 to get me my next one. So far I am very impressed with these guys. All CDs have been in good shape, short turn around, and no late fees, which used to kill me. My only complaint, and it is a minor issue, is that you can only have 2 out at a time. Because of the flat rate, I try alot of games that I normally wouldn't waste money on individually. So if I get 2 stinkers together, then I have to wait for the turn around time again to get some desent games.
So I guess to answer your question, while I have the bigger subscription, I still think it has to do more with your proximity to a Gamefly regional warehouse than if you pay more a month or not. And I can't think of a better hobby than this one. Carple Tunnel, muscle attrophy, lack of sleep. What could be better?