I said that I trained with him in the '80's - that was almost 25 years ago and since then I've trained with a number of other groups, including with Iwama groups and with Morihiro Saito in Iwama.
I just preferred the Yamaguchi teachers that I've trained with - that's a personal preference, as much to do with personality as anything else, it's not a statement about different styles.
I've also trained with Yoshinkan groups, and spent a few years in Daito-ryu, and others. I've seen the elephant.
So...what's your elephant? And does it make an iota of difference to the discussion?
In the following "you" is used loosely to refer to you and the group of people mentioned in one of Mark's posts. Consequently I am oversimplifying in a big way, correct me where you see fit.
At some point in your training you decided that the martial art that you practice lacks a certain quality that you believe the Founder possessed. It is then logical to ask yourself if your main teacher
(by main I mean the one that influenced and shaped of your art the most, this kinda extends to a group of "main" teachers if that is your case) possessed that quality. Then you apply the question to your teachers teacher etc... until you reach the Founder. This chain (or, less convincingly, a bunch of chains) is your lineage.
Using D Harden, M Sigman, Aunkai etc... as the source of that quality from outside of your lineage indicates that you believe that that quality is not present in your lineage any-more. It is then reasonable to ask at which transmission step was it lost.
My comment about the "standard, postwar, Kishomaru/Tohei, student experience" and before that, about "Aikido that came out of the Hombu dojo after the war" is just a shorthand for the
(I would have thought by now uncontroversial) fact that those students have seen the Founder once in a blue moon and trained under him even less. Consequently it is very likely that those students were, to a large extent, finding their own way, sometimes producing brilliant stuff such as the Nishio Aikido, but never having that quality.