Everybody and their cousins are talented swordsmen in this show. However, they all still have their own special skills they invested most of their time into. No matter how well you know that skill, it still means little because it's not your skill - unless it has some huge weakness the knowledge will open for exploit. But I hardly see Byakuya's techniques having such (despite the bullshit in this ep). I guess it's a moot point anymore, all things considered, but in addition to his sword's special abilities, Byakuya's particular skill was speed. Only bankai Ichigo and Yoruichi were able to beat him. Now some human, of all things, can beat that speed as well. You'd think a normal corporeal body would see some tendons snapping and muscles cracking at accelerations like that.