Re: Tanden Rotation
Well I certainly don't think he is mouthing off, he has no reason to-- if his sensei didn't make him feel pressured to report this sensation then I don't see why he would be outright faking.
But you seem to be saying that by feel (compared to all your other IMA teachers), he doesn't have what they have?
So maybe he has been exposed to certain ideas and is matching up what he feels personally with what he has only read/heard about intellectually?
Sorry my post has more questions than answers (I don't recall any of my aikido teachers saying anything about tanden rotation). I personally would be surprised at internal development that comes from practicing waza alone-- if the waza were used as complex neigongs, then that would require much explicit attention in the teaching and the learning, and it sounds like he isn't saying that. I think it is easy to think what one has heard about is the same as what one is personally feeling-- sometimes the words just match up, even though they are 2 different things.
For instance, tanden rotation and gyroscopes both have "rotation" but it seems weird to me to compare the two. One is a slight twisting (direction can be up/down or side/side, much less than one full turn) that loads tension into the body, one is a free, rapid, tension-free spinning in a single direction. If I understand correctly.