Japanese version > Korean version. This fits nicely with the sweet R&B tunes of Namie Amuro, JUJU, Koda Kumi, BENI and Kana Nishino TBH. Key Of Heart is one of BoA's best choreography, I will not tolerate any shade! Woo Weekend had a nice choreography too, though I never liked the song.
The covers are pretty dull though, but the Korean versions aren't any better either. Both of them have been meh, I have no idea why BoA's covers are always a mess... to me THE FACE was her last good cover.
EDIT: I take that back, Milestone was beautiful.