The whole time I was doing it I kept thinking "Good, god, I could use this in the dojo with new students." Take the yoga exercises. It starts off with just standing still and breathing. You stand on it and the screen shows a representation of you on the screen with a graphic "target". You try to adjust your stance so that the dot which represents your "real" center is in the center of the target (the optimal center). It is subtle. Very subtle. My wife who doesn't do anything like Aikido had some trouble getting it to stay, but she did all right. My mother-in-law had a lot of trouble, but that's what we're working on. I got up there and I was nearly dead center as long as I adopted that mental attitude of "aikido" movement and stance.
have someone push you lightly from the 8-compass directions at shoulder level and see if you still keep the center. hmmm got to try that but i have to fight my kids for it first.