I very much liked George's post #48, especially this
As someone who clearly prefers the "force of nature" style of Aikido I can see why you wouldn't like this. I am sorry but you are wrong about this. The surprise is definitely there when you deal with someone like Endo. It's not in the timing changes or some violent assault on the partner's structure, which is what you are used to. Endo, Yamaguchi, Takeda, Saotome Senseis all focused on "absorbing" the power of the attacker. You grab them and you feel nothing. Your balance breaks and you are not sure why, you can't figure out where your power went.
It sums up practicing with Endo sensei and Nakao sensei very well (I've not had the pleasure of practicing with the others). They work tirelessly on Aiki, working in unison with your attack, totally synchronizing your movement with theirs so that you can do nothing but go where they guide you. There is no resistance, nothing for you to get hold of, no obstruction, nothing to clash or fight with, just a void for you to fall into.
It's a great feeling, like George, I recommend you try it for yourself.