If it's a weekend trip, then a stay at the Dolphin or Swan is worth it to earn the points. Especially if you're gold or platinum with Starwood and can get the lounge access, but don't expect much more in terms of an upgrade.

If it's longer than that, then it's probably worth it to go for a "real" Disney hotel. The Swan/Dolphin don't have the Disney magic (those who've stayed before know what I mean), and don't feature all of the Disney benefits (like room charging and resort package delivery).

I would venture to guess that I've been to Disney more, and stayed at Disney resorts more than anyone else on these boards. My favorites are the Grand Floridian and the Boardwalk, but as always YMMV. FWIW, I highly recommend paying for concierge service at whatever resort you choose. The rooms and the services make the additional cost quite worthwhile.