Swan - more adult like - less kids stay there (reasons below).
From your picture - you look like a young couple with no kids.
Dolphin - has the game room for kids and laundry room for mom, Also has a 24 hour snack bar for the refillable mugs
The Grotto pool is wonderful - 3 parts, one side for little kids and familes, middle for bigger kids and families - has the water slide (adults go down too) and a water fall (romantic to sit behind it), other side has a volley ball net great for teens, young adults.
There is also a quiet pool near the Swan, a lap pool (adults only) near the Dolphin, a hot tub and a kiddie pool.
The rooms have all been recently renovated with calm colors and heavenly beds. Swan has 2 queen beds, Dolphin 2 double beds 9about 1" less wide than the queen beds). My guess king beds are also available.
The Dolphin has more rooms than the Swan.
Both can have great views of fireworks - ask for a balcony and lake/resort view.
Rates - great if you are a teacher, nurse and I think miltary. They also may offer
AAA or AP rates.
The Swan and Dolphin are owned by Starwood. not Disney.
They have some Disney items in the gift shop. No Disney wake-up calls or Disney soaps. No sending packages back to your resort or charging meals to your room key. No meal deals with Disney. No ME transporation from the airport.
Yes - early and late Park admissions, yes transporations - like Disney to all the Parks. Yes - walk to EPCOT, boat to EPCOT or STUDIOS.
Yes - you can have a great rate at a Deluxe Starwood resort.
We like the Dolhin - but have also stayed at the Contemporary.
We have a reservation for next year at the YC & Dolphin.
Then best rate will win where we stay.