my instructor is a 3rd dan aikikai who got his 3rd dan after more than 10 years which I guess is quite some time in aikikai and he was some kind of a "street" person so he tends to get into some fights. but 95% at the time he was teaching class, he always teaches henka waza. I have no problem in learning something new, but the problem is when I think some of his henka waza isn't effective. I know this because I have been the one he used as uke most of the time. when he's doing the technique, there's an opening for a punch or a kick or elbow strike which doesn't occur as much in kihon waza (that's why I like kihon waza and repect O Sensei so much for his research on human body). in some other times, I deliberately loosen my grip so that he doesn't look bad when performing a technique.
I know I should respect him for teaching. maybe this is just a rant or sharing.. but I would like to know if anyone has had similar experience..
When I did my Ikkyu test with Kawahara-shihan presiding, he remarked that while I was doing some pre-rehearsed henka-waza, MOST aikido is henka-waza..
I think it means that nage initiates, causing uke to attack, and then nage does a henka...
However - others have remarked that perhaps the openings are there because he's teaching stuff at a relatively low pace. I've had people pointing out the shortcomings of a particular technique that I've been trying at low pace, only to change their minds when things got going and there wasn't the time available to regain balance between stages of the technique. Maybe if your sensei were moving at full tilt and you'd really been attacking, he wouldn't have given up so many openings. If he does give up openings at more 'live' speed, perhaps he needs a reminder about the openings - an open palm light strike to the opening, perhaps, which might serve to wake him up and fix his teaching... Not sure if it would be appropriate to do this while the tech was being demonstrated... Perhaps during the practice with your partner stage, you could ask the sensei to help you understand better, and point out the openings (if they're truly there). If they do exist, a good sensei will call the group together again, acknowledge your input, and teach how to avoid leaving the opening.