For those who have seen this...

Watching this version now for the first time. Don't know about the ending yet, but the Kingsley/Lumley version is different from the Sondheim one most are familiar with. (For one - no American investigator.) This version seems to be of the "historical accuracy" variety - society, fashions, etc.
My sister and her boyfriend both saw the Depp/Bonham-Carter version - fairly faithful to the Sondheim musical, but bloodier. They highly recommend it.

Hope that helps!
P.S.
Ben Carlyle has just broken in to the pie shop and is face to face with a recently killed, um "pie filling." The ending I'm familiar with deals with a falling out between Tood and Lovett - not a fight to the finish between Carlyle and Lovett/Todd.

A barber murders a couple people and his neighbor sells them in pies. That's the only thing the two versions have in common, plot- or character-wise. I watched it this evening, and I tried to like it, but I have to say I'm disappointed. It was pretty bad. Probably the reason I didn't like it was that, without the Benjamin Barker backstory, Todd and Lovett are straight-up unsympathetic villains, and the "heroes" are not very appealing either. AND THERE IS NO MUSIC!

This is just my opinion, make your own judgments. Both versions are different takes on an English urban legend that's been around for a few centuries.

***Spoilers***

Check out Wikipedia's entry on "Sweeney Todd." There is a long tradition of this story. This particular version has a more complex backstory for Todd who is already a cannibal when he arrives on the scene, there's a large plot about retreiving some lost diamonds, relationships are shifted ("Lucy" isn't the same character here as in Sondheim's version); and there's no attempt at sympathy for the motives of the murderers here.

There's a greater focus on uncovering the mystery of disappearing people, an almost CSI investigation (that I found historically questionable), and a lot more eating of pies than we get in Sondheim's version. "Toby" plays the same role, although is even younger than in Burton's film and is a mute (clever, and the young actor is even better than in Burton's film), and, yes, he plays the same role in the final moments of the film. Mrs. Lovett's end is met at the hands of the law and not by Todd.

It's not a "bad" version of the story, although it certainly isn't moving the way Sondheim's piece is. Dwelling on the unpleasantness--if that's your thing--seems the purpose here.