I have to say that we were on the Destiny in March and had the time of our lives. We used to do all-inclusives, too, for years and hesitated on a cruise. We are not doing land-based vacations hardly anymore. It is great!
On San Juan, we thought it was a rather dirty and kind of scary at times... Make sure if you go a day early that you get an ocean front hotel that has a high rating and I think you would be fine...
Have fun!