We've been to both resorts and no matter which you choose you'll have an awesome time. With that said we like CTI but LOVE CSA! We don't need an au naturale experience so that feature of CTI didn't come into play when we booked CSA. Women do go topless on the beach but walking around that way is not permitted. At CTI you'll get a hotel feel but at CSA you'll get a beautifully landscaped spreadout experience. If you don't need to visit Dunns River Falls then the excursions are just about equal with the catamaran cruise at CSA better. We haven't been to the new sports facilities at CTI but the ones at CSA just can't be beat. They offer free tennis lessons and have industry certified instructors for aerobics, yoga and spin classes. The food and bars will be good at both. At CSA we love having a ground floor room and walking in and out of our verandah onto the beautiful grounds. The last thing that makes CSA the best is being on Seven Mile Beach. You can walk for miles down the beach and visit local shops and bars that you can't do at CTI.
I hope this helps and enjoy your time in Paradise no matter which resort you choose!