Well If im not too late the complete version i believe has some extra footage on it and a bunch of stuff and prolly looks better since its blu-ray. So...great movie!
My mom actually just bought the BluRay version on friday. The bluray version is high deffinition [obveously] and has 30 minutes more about that kid you see in the movie. [If you haven't seen it yet before I won't spoil it for you.]
I'm pretty sure it has some behind the scenes and making of and other things that bluray always has.
Though i'll double check for you.