Mike Sigman promotes IT to develop IS (internal strength) and Dan Harden uses the word "aiki." Are these two things the same? I know that the two gentlemen have some differences of opinion, but do they agree on the result of IT?
Also, how would one know if someone had mastered IS/Aiki? What are the specific things they can do?
The specific feel, if you've never felt it before is downright weird. You feel your balance taken on the point of contact, even before they visibly move. As for specific demos, look at youtube for old videos of Ueshiba taking pushes to the head, the jo trick, and other situations which seem to require a lot of "strength" to accomplish.
Aiki as I see it, is a manipulation, a subset of IS(kill), backed by IS(trength).
Akuzawa holding someone back who's pushing on him while he stands on one leg is a specific demonstration of I(Strength & Skill).
You're in Japan, you should come check us out when you're in Tokyo