basically the bottom line really depends on your teacher and their philosophy on weapons training, Ken teaches you technique whereas Jo teaches you principle. Most people are split between whether Aikido is a empty hand art or not. Honbu rarely if at all uses weapons, here in the US it is only required usually at advanced levels. and then either tachi dori or jo dori. with their particular "styles" of kumi waza. I have an open weapon class each week. which I use to expand on taijutsu and on the traditional use of each weapon, but you will always need to remember Aiki Ken and Aiki Jo are not the same as Ken or Iaido and even jodo. They are their to teach you aikido not to teach you to become a master swordsman. As the sense that training in Aikido will not make us Samurai. Although an active imagination is a wonderful thing...