Hi!
I used Travelocity for a quick trip in early May to Wilderness Lodge. I got a great rate (I think it was about a 30-40% discount) and was even upgraded from Courtyard View to Concierge when I checked-in! I also had a good experience with Travelocity's customer service when I called them on the phone with some questions about the booking. I would book with them again in a heartbeat if they run another sale when I plan to visit WDW.
I had considered Orbitz but they did not include Magical Express with the booking and when I called them to clarify this issue, an hour's worth of calls to their customer service number left me very frustrated.