As far as I know, the film just got a quickie Engrish dub for the DVD. There isn't really an "American version".
The BIG difference between the R1 disc and others is that the color timing appears to be wonky on the R1. The R2 (and probably the R4, Madman disc) appear to be better in regards to the color. The difference is significant. Check out this screencaps toward the bottom of .

