Re: knowledge is power
"If students try to use big, slow movements in a life and death situation, they will be killed. [/b][/quote]"
I don't think it is that absolute. Sure, squaring off with another martial artist irimi techniques can give you the "secret-edge" you need to make aikido work, but most assualts are suprise attacks and I think that tenkan movements lend themselves well to responding to an attacker who is already on top of you.
Also, mucking around with mates, I found I got in trouble if I sped my aikido up to their timing rather than slowing them down to my aikido timing.