Skorzeny, when I said randori I think I got the name wrong. I've been reading BJJ and judo forums lately. I studied Seidokan Aikido (
www.seidokan.org) at the University of Texas Aikido Club. There's a nice chart showing the lineage at
http://www.stillpointaikido.com/AboutUs.htm
Bill Sosa studied under Kobayashi, the founder of Seidokan, although Sosa's dojo isn't listed in the main Seidokan site.
The traditionalist argument is that, as you progress over a few years, the attacks get more realistic, and you will learn to use Aikido against a jab, cross, hook, etc. I hope to go back to Aikido and learn those techniques some day. But for defending myself on the street, I think there are more practical options.
I think the police use kote gaeshi and other Aikido techniques more as a control either in controlling a suspect or weapon retention/disarming. My dojo taught it more as a defense against an attack, where the uke was giving you the limb and momentum to work with, as Krept mentioned. The fact is, though, if your real-world opponent is dumb enough to give you those, and you are psychologically prepared for the fight, there are 500 things you can do to pound the guy. The hard part is learning to spot the opponent telegraphing his move at the instant he really commits to it. That skill really comes from sparring, which is done in only a limited form in Aikido.
To get back to the original thread topic, practical self-defense styles such as Tony Blauer's are good because they help you to detect and defuse potential fights before you have to defend yourself. If those tactics fail and you come to blows, Blauer's techniques will work better in the "oh sh*t!!" moment of the initial attack, when you're still in a state of fear/disbelief, and your timing and dexterity are 20% of what they are in the calm confines of the dojo.
Hours of practice with irimi nage, kokyu nage, and other throws helped me to learn to sidestep in boxing. Beginner boxers do tend to lunge forward and put their weight into punches, so it's easier to make them over-extend and lose their balance. The principles of balance are the same in any martial art or boxing. It's actually fun to play with my boxing buddies (with their agreement), trying to mimic an Aikido type of move when wearing boxing gloves and headgear. Irimi nage is a good example. You can do a sort of kote gaeshi move if the guy tries to do a big haymaker which gets him off balance. Kokyu nage can work sometimes, since it doesn't require a wrist hold.