Actually all the Real's are in Playa del Carmen, the Royal is right on the beach across the street from the Gran Porto Real, the Real Playa del Carmen is on 5th Ave and Calle 34. We stayed at the Gran in March 2005 and at the Real PDC March 2006.
It was nice being right on the beach but for the price difference you can't go wrong with the Real PDC.
A Good place to hang out downtown to people watch is the Tequila Barrell right on 5th or one of my favorite places to go for the live music is the Fa Bar at the Siesta Fiesta right on 5th. You will find many nice little restaurants/bars along 5th to sit and enjoy a cold drink or a nice meal. Don't be afraid to check out different places. Also some very nice places off of 5th, take a walk down some of the side streets, you'll find places like the Beer Bucket and if you like to dance try out the Mambo Cafe and a trip to Playa isn't complete unless you hit the Blue Parrot beach bar at least one night.
Enjoy, wish I was going back soon.