They are both nice but different. They both offer different types of rooms and a CRT discount.
The Presidente is your typical 3 star hotel with restaurant. They also have a small sports bar and casino attached. Working girls are not allowed to "hang out" there. The Presidente will often have families, backpackers and high school K*ds (like last weekend).
http://www.hotel-presidente.com/main.cfm
SL is sort of like a "home away from home" with a touch of frat house feel. SL clientele is almost 100% made up of like-minded guys. The rooms are appointed nicer than the standard Presidente rooms. I don't know when the new rooms will be available but you may get a shot at being one of the first to enjoy them. There is good food available in the bar.
Also at SL you will meet many CRT members and there are ladies who drop by to see if there are any gentlemen looking for companionship. It can be noisy in the bar area but usually quiets down by 11 during the week and midnight on weekends.
http://www.sportsmenscr.com/
I would suggest splitting your stay between the two then you'll know which you like better for your 2nd and 3rd and 4th trips. I would also suggest booking your rooms as soon as possible.
Welcome to CRT.
Wit