If you haven't seen it already try the Punta Cana section here...
http://palladiumaddict.net/
There is a forum on the site that is usually pretty good for suggestions, tips, etc. My wife and I learned a lot from it when we went to the Mayan Riviera a couple years ago. It is run by a group of people that almost exclusively travel to the Palladium resorts so the info there is quite specific to the resort you are going to. Most of the members are from Canada and the USA so the perspective is a little closer to home as well.
Keep in mind as well that some of the statements are a little biased but for the most part it is pretty true.