I'd say that the Swolphin is a "mediocre deluxe" rather than a "superior moderate". It has interior hallways, room service, valet parking, fine dining, and other trappings of deluxe hotels, and share, with the BoardWalk and Yacht and Beach Club, perhaps the best location in all of WDW. However, they are not Disney resorts, and often folks who are used to Disney's hotels really notice the difference.
You can reserve rooms for the two resorts here:
http://www.swandolphin.com/reserve/reserve.html
There may be better places to look up rates, though.
The level of service is the same between the two, as is the quality of the accommodations. The Dolphin is more of the "HQ" which is both good and bad. When there is a big business conference, it'll be focused most heavily at the Dolphin rather than the Swan. Really, really big business conference will utilize both resorts fully, and spill-over into the Disney resorts as well.