I miss everything but the music, I don't have to miss that. Oh yeah!
It did have some great characters: Garbonzo, Willard Warbler, Houdelini, Hilda Bovine, Lionel Burymore, and of course the infamous Maestro, "the true phantom of the theater." The part I miss the most though would have to be the pepper's ghost illusion in the "theater." That always amazed me, as I had no idea how it was done.
Phantom Theater