We have stayed at POR Riverside a number of times and the one thing we always commented on was all the COUPLES with no kids - we assume many were honeymooners.
I think their pool area is better geared for you. It is very large - kinda an L shape - where one end is the slide, baby pool and family hang out. The other is deeper, waterfall and by the jacuzzi and bar. It was almost like "adults only" feeling to us with kids.
If you are without car......POR is very centrally located and felt the transportation from there went very well. Also can take a boat down to Downtown Disney and that is a nice ride.
Coronado is great but it was very much kid/family oriented pool that had a large number of seats very much in open view. Jacuzzi huge but then full of people. I loved the hotel, but I don't think I would want to be there for my honeymoon. Also a convention hotel, so can be very busy with business people (and their families in tow).
Caribbean is just not one of our favorites. Pretty buildings and white sand, but very spread out. Pool areas very crowded. Very disappointed with food areas. Had the least amount of "customer service" there. Even though the caribbean theme, we felt like there was no privacy anywhere.
Wish I had gone to Disney on my honeymoon - enjoy!