I was at the Sheraton Nassau on Cable Beach about I guess 3 years ago. It was nice. and I would go there again. but it wasn't super exciting either.
The pool area was nice and the beach was nice. pool drinks were "reasonable" priced. (but not cheap by any means).
It's connected to the Wyndham by a 'tunnel' which is a shopping corridor. You have to go through the Casino's as noted above. The Casino's were pretty dismal. Nothing like Vegas Casino's.
Unless something has changed, you have use of the pool and beach at the Wyndham also.
CONSTRUCTION WARNING:
It's my understanding that at some point that the are tearing down both resorts and building a "mega resort" to rival Atlantis. I don't know if they've started this or now. You might want to google around and see if anyone is having any issues with this. they are supposed to tear down one first and then the other.
this is confirmed by this on Trip Advisor
"GOODBYE WYNDHAM & SHERATON, NASSAU, BAHAMAS" - Review of Wyndham Nassau Resort & Crystal Palace Casino, Nassau, New Providence Island - TripAdvisor