Inspired by the pick up heel comments I remembered this video
It starts about 10 sec in. and he describes the difference in the origions of the 2 postures in martial arts.
Then gives a demonstration of aikido vs karate and continues with a disscusion about the different breathing patterns between east and west.
Then afterwards he visits a man with 38 dans and talks about how aikido has become a sport and not a battlefield art.
Very big discussion on it here. Alot of crap there, but Sinister's real name is Louis Monda, and he is a top trainer at Johnny Taco's in Vegas with a few pro boxing fights. He at least knows what hes on about.
http://forums.sherdog.com/forums/f11/battles-posture-positioning-2358741/