I have now played at FullTilt, UltimateBet, and
bodog....and I can tell you that at all 3 sites I have seen players swear up and down that the site is rigged and that "such and such a site is less rigged". This is BS. All of the
online poker rooms use the same type of randomized card generator thing. They may differ a bit, but they are generally the same.
As far as UltimateBet, well, if you are playing at 50NL+ they have the Bad Beat Jackpot...but from my personal experience it sucks. They take .50 from every pot and it really kills your winnings. I ended up cashing out and deposited on FT instead.