I came up in ITF/USTF school. We did the Chan Hon sparring. Back when I did tournements it was alot of fun. While I only did a couple of Kukki style matches it was kind of strange.It seemed so unnatural for your opponent to be standing there with his hands at his sides. I was almost DQed for just faking like I was gonna head punch my opponent.I didn't really enjoy the whole "playing footsy" tag thing. Then again that wasn't the style I was training in.
It just seems weird to not be concerned about catching a face punch. I've moved on to traditional Karate and enjoy it very much. I guess it all comes down to what is your motivation to train. If it is pure sport (no SD) then kukki style TKD is probably for you.However, if you want to learn some self defense and still compete in sparring the Chan Hon is a better choice. I will also qualify my statement by saying for Self defense I would use a few of my TKD techniques, but most I wouldn't. It comes down to a question of range and having a good base.