Nice blue water but we did not go on the beach. Not much to see around town. We did go to the free rum distillery tour (John Waitling Distillery) which was about a 15 min walk from the port. Senor Frogs was somewhat lively. All in all, worth it for a couple of hours. Maybe consider booking an excursion here to eat up some more time.
Beautiful beach - definitely one of the nicest I've been to. They had lunch available for free, but I didn't eat on the island (ate back on the boat instead). We did the stingray excursion and it was great - swam and fed stingrays and only paid about $30.
One tip - when it's time to get back on the boat, you have to line up and wait for small ferries to take you from the island to the cruise ship. Do not wait on this long line. Instead hang out by the bar and wait for the line to die down.
Beautiful clear blue water but the beach was VERY rocky (not just small pebbles, but large rocks that made it difficult / impossible to go in without proper footwear). Bring flip flops or better yet water shoes.
Aside from that, there was not too much to see in the shops. There was a town a couple of miles away that required a taxi or bus to get to. We did not go there. However, Margaritaville was a lot of fun - a DJ was playing modern dance hits (hip hop, dance, etc.), and there was a very young spring-break crowd there.