The story was pretty ridiculous.
SPOLIERS (well plot outline of the first act, but avoid if you don't want to know)
It is set about 10 years after the original story (depending on what bit of the text you base it on...). Then he escaped away to Coney Island, New York, where he runs (from the shadows) a freak show/cabaret review, with both Meg and Madame Giry. Christine is now a world renowned opera singer, and is lured to the US to open a new opera house with Raoul, now a gambling drunk, and her 10 year old son. And thus begins the fight for Christine once again.
It is all pretty odd and doesn't really feel part of the same world as the original. That and it looked a bit cheap. But I think the problem was is people like POTO's original ending, and a sequel wasn't really needed. Kind of like going, "And then they lived happily ever after! Except..."
But the score is my favourite of Lloyd Webber's, and so I would go just for that.