I took the Walk in Walt's Footsteps with my wife. When we went, there was no headsets, just a guide talking. We got a pin and lunch at the Golden Horseshoe, and we were able to go into the Lobby of Club 33. We loved it!
We also did a tour called Mysteries, Myths, and Legends on Halloween one year. I don't know if it is like the Happiest Haunts, but it was fun. We got to walk around the parks after they were closed and ride certain rides. We went on Tower of Terror, the bellhop said "Enjoy your stay.", and we rode the ride. When it was over, the doors opened and he said "Enjoy your stay, AGAIN!" We got to ride it again without even having to get off. When we rode The Haunted Mansion our tour guide was waving at us during the Ballroom Scene. It was so awesome!