My teacher had me working a counter to mawashi geri that spun into that low ushiro mawashi. I was skeptical until I got hit with it.
Shihan Quinn is a great person and a great teacher. He's looked at a video I took of myself kicking and helped me figure out just what I was doing wrong before. Willing to talk to anyone, respectful towards all. Some time he has promised to come train with us, as he has a sister who lives in the area, but so far he's been too busy.
I've spoken with people from many different IKOs who have had him do a seminar, and they have all said he was great. He's willing to do one here in NorCal, but I'm not sure I can get enough knockdown people to come to it, and his price is pretty steep.
I love leg kicks. I am short with little short legs to go with my short t-rex arms, but with gedan mawashi geri, I can really turn my hip over and drive down, bringing all my hamplanet mass to bear on someone's thigh. I'm a shitty fighter, but I still love gedan mawashi geri. That and hiza geri are my favorites.