Text speeds have yet to be fully timed, but Japanese is currently known to save ~2 minutes over English.
The European version also has French, German, Spanish, and Italian translations. Italian is currently known to be the fastest, it is beleived to be slightly slower than Japanese but not as large of a difference as English. No precise timing has been done to verify this.
(Exact times will be added later)
The European version is based on an earlier build of the game and has various differences to it. The North American version is the latest of the three and fixed some glitches. The Japanese version is in between the two and is also the preferred version, as the Portal Items glitch wasn't patched and Zeffa can be called from the top of the Wind Palace unlike the European version.
USA: Beanstalk Theme
JPN: Beanstalk Theme
EUR: Quiet Town Fest Theme