The UK version contains re-dubbed/additional dialogue compared to the US version. Both cuts are identical in terms of visual content, but there are approximately 30 aural differences between the two.
The UK version doesn't have extras unlike the US version.
The UK version was also shown in the U.S. as a pay-per-view event. Runtime for both versions, as well as the Argentine release, is the same, since the only (slight) differences are in dialogue and music.