We were in the same dilemma and after reading some reviews, decided to go with the GC. Also, yesterday there was a segment on the Travel Channel about it, and it looked gorgeous. I know we will probably not be visiting DL again anytime soon, so wanted to do it as nicely as possible.
Have you tried Travelocity for rates? I believe you might be able to get a better rate at the DH than what you mentioned.