I know aikido students love to tell tall tales about the exploits of the master they chose. When did Nishio ever win a challenge match against a sumo champion, or a judo champion? Better yet, in his time he should have been able to effortlessly toy with a UFC heavyweight champion! When did he defeat a iaido master with a live blade while he was empty handed or allow a firing squad to shoot live ammo at him? Hell, when did he even tell a group of regular guys to attack him in any way they wanted so he could prove what you call his technically improved version in a context other than having his own students "attack" with something other than a telegraphed shomen uchi? I know, I know, he could have done all that easilly but it would have been against the "aikido spirit" you speak of. Ueshiba was only able to do these things because of superior technique, not speed or strength from "air rowing", deep breathing or prayer!
Your comment is the perfect example of what the other poster was talking about. You never wanted to emulate the founder because you never witnessed these things because nobody was alive who could do them right in front of you so you probably think that they are myths and impossible for your teacher, you, or anybody else to do so you "don't want to do be able to them"! I bet that Nishio himself would disagree (or would have disagreed? I can't keep track of which of the old timers are even still alive) with your statement himself.