I'm also not shocked. Not that the quality of the show has anything to do with it (like the previous post said, it's the name recognition), but this tour is excellent. As someone who has seen MM dozens of times (on tour, on Broadway, in the West End with the OLC, and several regional productions) I went into the tour recently sort of dubious it would be anything different from the same jukebox frivolity it had been the last time it was in my neck of the woods. Imagine my surprise to find the show feeling fresh and purposeful, with performances that for once made the show less jukebox (just hit play whenever they felt like it) and more one that incorporated the ABBA songs nicely into the action. We had an understudy for Sophie that I didn't even realize until intermission, but she was terrific. The three ladies were wonderful (I've never heard Tanya sung that well), and even though Christine Sherrill loves to backsing a bit too much, she's played Donna all over the place and has really perfected the role -- her vocals were really thrilling.
Here's hoping they keep that energy up and don't let it wane as the cities pile up.