Just to be clear, I did not intend to give my own opinion about your aikido with my previous post. I think the truth of what you are sharing would be more convincing if you trained with others, but it is your business if you choose not to do so.
Regarding what I felt from Endo Shihan, as Carsten described before, it felt like nothing, but in my case this was because nothing happened. I would like to stress that it was only at a seminar and I only got to take ukemi twice. I was unsure of what was being worked on at the time. Some people looked like they were taking dives for him (not necessarily sensei's fault) while others looked like they were giving meaningful attacks and genuinely resisting him. Whatever was required, I got it wrong and got a telling off for my trouble and then someone came over to teach me a "lesson" afterwards (again not sensei's fault). I'd still like to get a better idea of what he's doing but I haven't had a chance to try his Hombu class yet.
I wrote a bit about it on Aikiweb already:
Thank you Carl. I found that very interesting.