Centrally located where? The onsite resorts are all in the same general area...with the exception that RPH is on the one side of CityWalk and is about a 5 - 10 minute walk to Islands of Adventure and HRH is is the other side of CityWalk and about a 5 minute walk to Universal Studios (unless I'm mistaken...?). The two resorts are VERY close to each other, just like the themeparks are very closer to each other. Within walking distance, or, if you'd prefer, take a water taxi from one hotel to CityWalk and catch another water taxi from CityWalk to the other hotel.
HTH!!