22s vs. 33s. vs 55s

[MuckedTheNuts]

I know I have seen numerous posts on this topic , but I have never seem a final answer reached. Here is my situation: I have played 582 11s with an roi of 20.0% and an itm of 38.7%, so after this success I moved up to the 22s. Currently my roi is 30.9% with an itm of 40.5% after 200 games. Now I know I have a small sample size, but I think I am doing pretty well. So my question is should I moved up to the 33s? Or just wait till my bankroll lets me go to the 55s? I have heard the 55s are much harder, and that is where most of the "pros" are. Is this still the case? Thanks for the advice.