Re: Shioda, Tohei, and Ki Things
Don't think my two cents isn't worth very much in this discussion (which is really good, btw), but I just have a quick observation about instructors and how they feel. Interesting how the feeling of advanced people is so similar.
My background is Shodokan; ended up at our hombu dojo in Osaka for a year in 1999/00 then went tripping about some. I bumped into Ezra sensei at a seminar in the UK. Over the course of nine years in aikido he had the closest feeling to Nariyama Shihan of our hombu dojo. I was almost tempted to journey up to Liverpool from the English deep south to train with him. (Logistics unfortunatey, were not kind.)
A signifcant part of the Shodokan system can be seen to focus on itoistu rokyu, kokyu rokyu and datsu rokyu (granted; exact definitions only valid within a school, but anyway). When I've felt Nariyama's technique and, on the one occasion, Ezra sensei's, these aspects felt very similar.