We have been at HRH, and absoutely love the pool there. We went over and tried RPR's pool, which was okay, but not as nice as the HRH in my opinion (never tried PBH's). HRH's pool has a cool slide, underwater music, and awesome music above ground as well (good rock variety, no rap or anything). The lifeguards play around with the kids (when we were there they had some sort of water balloon contest thing where the kids had to protect their balloons, and all the guards snuck up on them and broke them) and waiters/waitresses are constantly walking around to get you drinks/food.
RPR was nice, but did not seem as "happening" as HRH, and I did not see a waitress at all (although they do have them, since there were menu's on the chairs, just no one around to take an order). The only place I saw to get a drink was to go up to the bar, but it was packed at the time with men who were dressed as though they were there on a convention. Well, being in my bathing suit.......I decided to forgo the drink!