I've been to PR a few times.  Unfortunately, the scene died long ago.  Here's a good history of it:  http://www.wikisexguide.com/wiki/San_Juan  
If you're looking for that sort of fun in the Caribbean, the D.R. is a much better time.
Tourist tip: Take the ferry from OSJ dock to Catano across the bay and catch a taxi to the Bacardi distillery.  Unfortunately, the tour is no longer free, but should be worth it if you enjoy such tours.  The best breakfast in OSJ is at the legendary Cafeteria Mallorca on San Francisco street.