I've been to San Diego and Santa Monica and it was beautiful.
Unfortunately, we were with our kids who at the time were 9, 9, and 14. Not the most pleasant way to travel. LOL
I went to South Beach for 3 days with my daughter, DIL and her family for the bachelorette party. It could have been lots of fun, but they are all very dull people. SOOOO, I never got to see the fun side of South Beach. I'd love to return and hit the fun spots. South Beach has amazing restaurants and night clubs. That's what it's all about for me.
Jamaica is all about fun. We go to an all-inclusive resort and it's all about the beach, delish drinks, jerk chicken, and partying at night. Ok, it's like spring break for the middle-aged. LOL