I'm big fan of Summer Glau and watch every movie she is in. That's why I'm 22 and watch this at first sight "child movie".
Summer Glau in this movie did excellent job! The sweetish elf I've ever seen. So much love and endless kindness. Only for this I can rate the film 10/10. I mean on of the best role she played. Terminator chronicles, dollhouse, 4400, serenity, help for the holidays - are the best movies with Summer.
But while I was watching it it was good movie. Yeah, really good movie - the actors played good (especially kids and Santa) - as for me on of the best Santa in the movies.
In some moments I even have a mood for crying.
Definitely 10/10 and you really should watch this.