I have stayed at the SL twice and loved each stay. Like a poster mentioned above, the bar closes at 12:00, and when you return to the SL after a night of partying the place will be dark and locked down. The security dude will let you in and lead you to your room. It is very quiet throughout the evening and early morning hours.
My routine is to go straight to the SL upon arrival to CR to drop off my bags. I'll return at around dinner time for a shower and pretty good food (the nachos kick serious ass). I'm usually out of there at about 6:00 or 7:00. The early-evening crowd is lively but not out of control by any means.
I have seen only two or three chicas at the SL at any given time. Was I just unlucky?
The SL is a great place to stay if you want a quiet room, good food, and good service. It is very chica friendly, i.e., no pu*sy tax.

I think it is the perfect place to base operations if you want to let it all hang out elsewhere in San Jose. But if you're looking for an experience like the DR, this is not the place. The age range of the typical SL guest is wide, but I've found that age doesn't matter much when mongering. I'm in my early thirties and tore up the town with a 60-something fellow gringo on my first trip. My second trip to SL also was alone and was just as productive.
Most of the staff are eager to help with the exception of one bartender who does not speak English - not real friendly. But that's about the worst I can say about the SL.