I went down in 2001 with some classmates from college - 2 of which lived in San Juan. First of all, both kids were daughters of doctors, so they lived in very nice gated areas that were within urban SJ; that is to say, it was like some of the nicer places in San Francisco. We had a great time in San Juan hitting up some clubs and casinos. It was like any other city I've ever been to with nice places and places you shouldn't go.
From there we went to a beach condo somewhere along the Carib side of the island, which was very very nice. The beaches were as white and sandy as virtually any other place I've been to, but they have American style stuff nearby - we even ate at a TGI Fridays one night.
I've actually been to several of the islands in the last 5-6 years, and the bigger ones (Jamaica, PR) are about the same with good and bad places, rich and poor places and some very nice resorts. Neither are going to resemble the very small islands with regards to way of life or scenary.
All-in-all, it was a good stay for me. Hope this helps.
