I just saw Sweeney Todd. I loved it. The filming is impeccable. The scenes of 19th century London are stunning. The story is captivating (they made some changes from the stage version that tightened it up).
I had read a review in The New York Times that said that it is as gory as Saw. I haven't actually seen Saw all the way through, though I think I can safely say that it is not nearly as gory as Saw. In fact, the blood is too bright red to be realistic. It's meant to be over-the-top Grand Guignol. There are some big gross-out moments, of course, but it's always in Tim Burton style - meaning that it's effective, but cartoonish.
The acting is great. The singing is not as good as you'd like, but it's no surprise. Johnny Depp had a bit of a rock-and-roll flair to his singing, which I expected. He hit the notes better than I was expecting. But his acting is just so good, you have to forgive him.
I had seen a revival of Sweeney Todd last year on Broadway that was excellent. I really shouldn't compare the two, because there's no coming close to how talented the cast was in the stage version; however, the movie has one thing that I've never seen in a stage version of Sweeney Todd - it's creepy fun.
I really can't think of anyone that I wouldn't send to go see it.