KBlade is for the intermediate moving to advanced range. The KSixOne is for more advanced players.
pretty much spot on. but if you're really being pedantic, both of them are a range within a range: the blade range has the team for lower intermediates, the blade for high intermediates and the blade tour for advanced players. the 61 range has the lite for juniors, the team for intermediates, and the 95s and tour for advanced players.