This is a good rate for the Doubletree. However I would be very tempted to take the Swan at $147 instead and recommend you do so if you can afford it. You will have to pay a $10 resort fee at the Swan (unless you've already included that).
The Doubletree is OK, it's best feature being that the rooms are enormous, about 600 sq ft. (This is more than 200 sq ft bigger than what you will get at the Swan.) You get two double beds and a sleeper couch. The furnishings are nothing special, not as nice as you'd see in an Embassy Suites. But you do get a cheap microwave, mini-fridge and sink. As with all the Downtown Disney hotels, the landscaping is very nice and the parking is free and more than adequate. (I recommend you have a rental car if you stay there.) It's an average 3-star hotel, not the best Doubletree I've seen, but a good value at this rate. The Swan is definitely 4-star.
I find it ominous that somebody else mentioned problems with hot water as I also experienced problems when I was there (Nov 2002). No hot water for most of a day -- they said the boiler was out, and hot water did return eventually. But it may be continuing problem.