I've stayed at the Dolphin (and Swan) and Grand Cypress, not the JW or Ritz. I agree that the JW Marriott may be a bit far if you're going to Orlando specifically for the Disney parks. I had a bad experience at the Hyatt Grand Cypress (it was my honeymoon, and we ended up LEAVING and going to the Grand Floridian, the staff was horrible but it may have been a fluke, the room was basic, you get the picture). I really like the Swan/Dolphin (although I have to admit, I've always disliked the skyline with the huge structures looming overhead, and it's a goldfish, not a dolphin...). But, the beds are so clean and comfortable, much nicer than ANY Disney resort we've stayed at. And I like the room service, the movies on demand (Disney resort TV sucks, sorry but it does). After a long day, it's nice to chill out and let the kids order a movie, get some carry out or room service and chill. Plus the service is really good, as opposed to much of my experience at Disney resorts, where it has been really hit and miss. The pool is fine, and yes I like the walk to Epcot or boat to MGM (we've walked it a few times, but it's about a mile I think, fine if it's not too hot, I don't mind the walk, but DD8 and DS10 get pooped).
It really depends on when you're going, but you'll get better than a deluxe disney resort room at the swan/dolphin (the swan has queen beds or a king, dolphin has double, just to let you know, and I liked the swan better, it's quieter) for a fraction of the cost. Swan rooms are smaller I think.
I can no longer do one room for DH and me with both kids. If it's just me with the kids, that is fine though. If you get a good deal, you could get two rooms at the swan/dolphin also, or have you looked into the villas (boardwalk?).