We've been to CN 3 x, CTI 1x, & CSS 1x.
If you are looking to branch out then I would suggest CSS especially if AN is important.
SSB is equally as large as the CN AN beach. The sand is soft, not as silky as CN, but still soft. There is also a large pool with enough room to float in and there is a cool waterfall that is a blast to get a water massage. There is a great swim up bar and we really enjoyed the beach. The entertainment crew come over twice a day and there is a chef who brings over lunch and stays the afternoon to cook burgers, fries, patties, etc. CSS really makes ANers feel first class.
I will say that we missed being able to float in the ocean. We did it, but it wasn't as calm as at CN. There is a river that runs just to the left of the beach and it runs strong enough that it actually changes the beach from day to day. Consequently there is a strong current that can take you out to sea if you don't pay attention, but we still loved CSS and are returning in 2011.
Since you already have plans to return to CN in 2011, I'd book CSS for 2010.
The only other drawback is that the beach is not good for long walks, but the AN beach is so awesome and there are so many fun pathways around CSS that we didn't miss long walks on the beach.
CSS is beautiful! It is simply magical. Go, you will enjoy and be mesmerized like the rest of us.
Juliann & Jeff
Jamaica Soon Come