We've been to all four.
If you are wanting a beach similar to CSA, then CN is the answer.
The age can range all over the place depending on the group there any given week. We have found the summer months appear to have younger crowds as many are on their honeymoon, but we've been in December and there are still younger groups there.
To meet people, all of the resorts offer that. Especially because all four have swim-up bars, it makes it easy to meet people. We aren't big swim-up bar people (more beach people), but we still made friends on the beach.
VickyJ is right about the beaches. CTI & CSS's beaches are in small coves. The sand isn't as soft as in Negril and the beaches are very small. Not good for long walks, but there is still plenty of room on both beaches for finding your spot in the sun or shade. We found the water to be bit rougher on the Ocho Rios side than the Negril side.
We also love the beaches of Negril, but have fallen in love with CSS. It is a very special resort. We couldn't decide which to go to next so we decided to do a split. CSS for a week and then CN for a week. This gives us the best of both of what we love.
The Ocho Rios side of the island is very different from Negril, but still a wonderful trip. And no matter which resort you choose, you will still get the same fabulous service and food. Plus it will be Couples, so how can you go wrong?
Juliann & Jeff
Jamaica Soon Come