Depends on your interests/tastes. PBH is more remote and quiet. It seems more formal, but I have heard that the atmosphere is relaxed and laid back. Great Italian food too.
The HRH is closer to the parks (about a 5 minute walk to US) and is a bit more hip and happening. We love the HRH. The theming is great and the music is too, but inescapable. Not too loud, but always present almost everywhere in the hotel. Rooms are quiet.
I look forward to trying the PBH if my husband and I are able to sneak down for a romantic weekend.