Sweeney Todd has to be the oddest musical I have ever seen, and that list includes Urinetown. (Yikes!)
But you know what? I liked it. The story was gruesome, true, but the actor/musicians were fantastic and the staging was amazing (one of the best things about our seats up in the cloud club is the view of the movement on stage -- the other best thing is how cheap they are!)
At intermission, we watched people literally fleeing the theater. I have never left a production or movie in the middle; I guess I always hold out hope that it will get better.
I have, however, napped. (See above reference to Urinetown.)