I have stayed at Sapphire Falls last December. It was nice and clean, but much more business friendly. Cabana Bay has fun value after hours. I am truly on site for the early entry options and flexibility.
IMHO you can't go wrong with any on-site hotel. I think they are all great and have various pluses and minuses (e.g. Hard Rock is a short walk to the parks, it's also usually the most expensive). That being said, if early entry is your top preference, why not do Cabana Bay again, seeing as how it will probably be the least expensive? You likely won't need the Express Passes offered by the premier hotels at that time of year, and you can put the savings toward another drink from Swizzle