We stayed at the Marriott Sabal Palms last month and loved it. The units are behind the huge Marriott World hotel and guests can use the World pools, water slides, restaurants, shops, Starbucks, etc. It's a short 5 minute walk to the World or they offer a shuttle.
The Sabal pool and hot tubs (2) are quiet and relaxing. You can see the hot air balloon and Planet Hollywood in DTD from the Sabal pool. The units are two bedrooms, 2 bathrooms, huge circular shower in the master bath, full kitchen, washer/dryer and quiet. There is also a pull out sofa in the living room. A LOT of room! There are only two stories and my recommendation is to get a second floor to eliminate any possible noise from an upstairs neighbor. There are no elevators but each entrance is private. The balconies that I saw overlook either the pool (which we had) or the golf course. I suppose you could ask for a pool view? There are two entrances to the screened-in balcony; one from the living room and one from the master suite.
The World pool is gigantic, with 2 waterfalls, hot tub, children's splash pool, outdoor restaurant and bar, multilevel decks, separate waterslides. There is also a pool near the spa which is really zen-like; playing relaxation music and calm. I almost fell asleep there! All the pools were very clean and well kept.
The Royal Palms are on the same property, but we didn't look at those. They seem to be a bit farther from the World pool and I would think you need that shuttle.
I'm looking into the Grande Vista for a *possible* trip in October. Haven't heard/seen anything about that resort yet. ?? We will definitely stay at the Sabal Palms again. The Grande Vista is a little cheaper right now for us for October (about $200) and Marriotts in general are usually really nice.