The Dolphin is somewhat less themed but is all in one LARGE building. The room will be bigger than at CSR and will have an interior corridor entrane. There are more places to eat at the hotel with many, many other places to eat right nearby and walkable. The location is great and you can walk or take a boat to Epcot and the Disney Studios. It is a more upscale experiance. But I love CSR and sometime I really think exterior corridors are quieter and the 3 themes sections are very fun, interesting and nice. You have the main pool and 3 quiet pools with one of the quiet pools most likely being much closer than the pools at the Dolphin.
In general if the prices are sililar the Dolphin is a better deal.