Besides the original Japanese voices there were SUPPOSED to be extra costumes for some of the characters. These costumes were available in the PAL collector's edition but weren';t included in the US one(I'm pretty certain of this).
The reason I wrote "SUPPOSED" was that it turned out that Atari screwed up the GH version and simply re-printed the original version(non-GH.. without the extras) onto the disk. I believe there were a bunch of topics about this on the Atari forums.... A LOT of people were seriously pissed(my friend included).
I haven't kept up on the situation but I remember that Atari was supposedly working on a solution, and you could send in your disk and get it replaced.
I'm wondering if something was done(replacement disks/recall maybe) because I couldn't many GH Budokai 3 for quite a while, now I see them in greater numbers with a really crappy shrink wrapping job.
I really hope they fixed this... I'll have to check out the Atari forums to find out.