I saw this at a NY preview, and it was very much worth my time.
Cristina Ricci was excellent. I thought it was brave and smart of her to take on this role, and given the make up and costume she was very expressive and genuine eyes, eyes, eyes. If any of you have seen "Pumpkin" this character would be a polar opposite of that role, but just as tongue and cheek, and just as much fun.
James McAvoy looked great, as was his performance. Christina and James had sparks that were believable. The supporting cast was also fun and fanciful. Catherine O'Hara played an excellent zany Mom which was more believable and real, in a weird way, then her role in Beetle Juice, (a film I adore.) Reese Witherspoon, was strong as usual, even in this odd, small supporting role (given her filmography). She looked great as a lower east side character. The only disappointment was Richard E. Grant, and not by his doing. There was no chance for him to shine given the part. Something tells me he got lost on the cutting room floor. A zero role for him given his talent.
In sum, I am one for magic and fables, so for me this was a very enjoyable film. I forgot the time which is the best test of all. Bravo!