I think there are too many variables to compare different sites in respect to winrates. I've been like yourself and been bonus whoring at numerous sites and I do have different BB/100 rates at each site but I don't take any notice of it as the games at these limits are so transient that it's difficult to play a substantial amout of games against the same regular opponents.

The rake at Party is better than some of the other sites you mention and the games are looser but you'll also find that your varience will be greater at party. I have the worst conversion rates at Party and find that I seem to make better head way in tight passive games. Maybe thats just the way my game is programmed but I like it. I don't think my heart can take sessions where winning and loosing 50BB's are regular occurences.

Best thing to do is step up to 2/4 at which ever site you fancy. It's not as tight as 1/2 in my opinion. 1/2 is full of people who have been working there way up through the limits, where as you find that a large number of people at 2/4 are there because they want to play and it's at a limit where they feel like they are gambling. Set yourself a limit on how much you are willing to loose and dive in. You'll be suprised.

Good luck

lorez