Just spent 4 weeks in Punta Cana in 3 different resorts and loved it. There was one thing that was disappointing at all 3 resorts and that is guests reserving beds in prime locations very early in the morning then getting up at midday then claiming them. Also the same people reserving prime beds on the beach and by the pool then claiming their pool beds around 4pm. We also witnessed big groups of people with adjoining swim up rooms also reserving prime locations around the pool and not using them to mid afternoon and sometimes not at all.
I think that all resorts should have a maximum time that any bed is left for. 90 mins is long enough to do most things and if its any longer then they should give it up then it could be used by someone that wanted it. There are always plenty of non prime beds