I've stayed in both. In fact, we just came back from the R&R weekend that you are looking for.

The Ritz Naples feels just like a luxury conference hotel. The hotel itself is beautiful, but big. Valet parking, front desk staff, etc. was a zoo. There tend to be a lot of conferences here, so be prepared for large groups of people running around with nametags. The staff is helpful but generally looked dazed just from the amount of people. My wife got a massage and loved it, while I sat by the pool (There are two, one for families and one for adults.) and read. Very, very relaxing. If you go, try to get a room with a view of the water. The sunset is incredible. This is a very good hotel for R&R, at least once you get your car parked. Rooms were nice, but not spectacular.

Orlando was also nice. Didn't use the spa, but the grounds are great and the staff is very good. Use of the JW Marriott pools next door is a bonus, as they have some great ones (including a lazy river).

I'd recommend the Naples hotel for R&R.

Mike