No opinion on tickets, yet, but as to DisneyQuest:

It is probably a good standby for a rainy day. There are many activities in the building. Some are obviously geared to older kids, teens, and adults (the design-your-own roller coaster being one example). There are several group video simulations which my 5 year old (at the time) nephew really enjoyed (being on a pirate ship and shooting at other pirate ships, rafting down the Amazon, etc.). There are many, many video games. There are also a lot of carnaval/county fair/arcade type games. And there a number of other type games. So it depends on the type of activities your girls like. Other than the sophisitication of some of the games and simulations, this is not especially Disney-equese. There are also no windows; much of it has limited lighting for effect. Unless the weather was bad, I would not shortcut MK, Epcot, AK, or a waterpark to take kids that age to DQ.

A few thoughts about the Swan: (1) you are within easy walking distance (or boat ride) to the back entrance to Epcot. That makes it easy to go see the laser show or otherwise pop into the park for a quick visit or meal even if you're not in that park all day. (2) Other than the resorts on the Boardwalk, you may find it a long and frustrating process to get to other Disney resorts using Disney transportation, several of which are worth visiting (Polynesian, Wilderness Lodge, Grand Floridian, maybe Animal Kingdom lodge). Either drive yourself or visit those directly from the MK (AKL in the case of AK); they make a nice rest stop for a meal or break. (3) Getting to the Epcot monorail was also a hassle in my prior visits: (a) go into the back entrance of Epcot and walk through the park or (b) take the boat to MGM and then take a bus to (the front of) Epcot.