Re: Dobson and Arikawa Sensei
I trained in Arikawa Sensei's classes many times in 1979 and 1980. Though training in those classes was very rough, and a lot of people got injured, I don't remember Arikawa Sensei himself ever injuring his ukes. When he threw me, though the experience was usually pretty painful, I never got injured, in that the joint in question didn't hurt the next day. This was not always true with some of the other teachers who had a less fearsome reputation.
I also did some training with Terry Dobson Sensei. While Terry was very good, very strong, pretty tough, and had some unresolved anger issues, my own belief is that in a real fight Arikawa Sensei would have destroyed him, even though Terry was three times Arikawa Sensei's size. Though Terry isn't around anymore to ask, I doubt if he would have disagreed.
Although Arikawa Sensei's practice was very intense and severe, and Arikawa Sensei was definitely very eccentric, I always found him to be a gentleman, again, not my experience with all the teachers.