I like Monty Python, and I enjoy musicals, so I thought it was hilarious. The songs are funny, the characters are funny, the dialogue is funny, the sets are cool, and the actors in this company are really, really good. Not to mention that they all have excellent voices, particularly Caroline Bowman, the Lady of the Lake.
Here's the thing, though. Some people, notably Judy, my wife, don't get this kind of humor, and if they don't like musicals (Judy doesn't), then all this is going to be lost on them. Judy loves A Fish Called Wanda, yet she got nothing from Spamalot. Go figure.