Thanks for the detailed review - if you like local places I sure hope you do try some of the ones off property - way better value and much more authentic!
For others I think it is important to remember that the beach situation varies tremendously - you have it good, when I was there it was quite wavy and there were tons of debris (including used syringes and palm fronds, etc) in the water as well as a form of sea urchin in the shallow water. Every day I saw people limping after encountering some in the sand - they were small and unlike the ones I am familiar with so hard to see and avoid. Bulldozers were needed each day to collect the garbage that was gathered by the hotel crew on the beach.
Other times I have heard (and you confirm) it is calm and like a glassy lake.