I've trained with a light and a heavy weight boken and get different benefits from them both. The light one helps me develop hip movement (I move my body faster) whereas the heavy one builds up my forearm muscles and seems to help my extension more. However the heavy one has quite a long handle and seems to develop the right side of my body more (I can't cut left handed after years of right handed practise and I'm not sure I should start).
I was thinking of getting a medium weight suburi boken now as I'm slightly dissatisfeid with both. How do you people feel about the weight of your weapon?