Keep in mind that's some really old footage. He's changed some over the years.
I think the hardest thing for people coming at Don's stuff from an Aikido background is that in order to really start to approach what he's doing, they have to realize that it IS different from what they were taught, no matter how similar it looks. Being able to accept that and let go of what they think they know is very difficult. Too often you hear, "Yeah, we do that too..." No, no you don't. (I don't mean that as a dig at you Boon, just a general comment.)
When we were at the first Aiki Expo I happened upon an old Aikido friend walking down the hallway. He said that he had just walked out of Angier Sensei's class because it was all BS and he couldn't take it any more.
I literally told him to get his a** back to the class, get up to the front row and not even think about leaving until he had personally put his hands on Don. Than if he still thought it was fake, well ok.
I met him in the hallway again two hours later and he thanked me profusely for saving him from making a fool of himself.
Yes, what Angier Sensei does is different from what Aikido people are doing. Absolutely. The question really is, should it be? In terms of outer form, size of movement etc there are reasons that Aikido is the way it is. But what the body is doing shouldn't really be different. When you look at a teacher like Yamaguchi Sensei and you see the level of relaxation he had at all times, the complete lack of forcing anything, I think you are seeing on an internal level the same thing you see with Angier Sensei (and Toby Threadgill, and Kuroda Sensei, and Howard Popkin, etc)
There is a line of teachers in Aikido who seem to have been interested in this. Saotome Sensei, Endo Sensei, Takeda Sensei are all from the Yamaguchi line and all have developed this relaxed, seemingly soft style.This is the only Aikido that I have seen that has much in common with what Don Angier does. The biggest difference is that Don's teaching methodology is superior.
As mentioned before, with the Yanagi Ryu, you start with exercises that are designed to imprint proper body mechanics. You can work for months on the smallest movement until you get it right. You don't go to the next step until you have completed the previous. It may take quite some time until you get to anything that even looks like a technique but when you do, your body knows exactly what it should be doing.
All Aikido people start by doing their techniques in a way that simply will not work. Then there is some expectation that after many many repetitions, it will change to something that will work. That is one of the popular definitions of insanity... doing the same thing over and over with the expectation that the result will at some point be different. To the extent that I started to figure any of this out, I had to stop doing what I had been doing and start doing things differently. The input I needed to do this came from the folks I trained with at the Expos, not my Aikido teachers. I redid my Aikido 100% after the first Expo and the process is continuing.
I can only wonder, how good could I have been if we had had a systematic teaching method which imprinted a proper understanding of aiki principle and body mechanics when I first started 32 years ago?