Gotta agree here. We have few guys (including the gym owner) with 2nd to 4th degree black belts that use maybe 1-2% of their TKD training. I've been training for just over 2 yrs and can hold my own standing with a 3rd dan in full sparring. He's 20 something. I'm 44. Needless to say I'm not that impressed so far with TKD. Sorry if I step on any toes, this has just been my experience.
i second this. The best (most usable) striking i have ever trained is muay thai. tkd will have you learning ridiculous kicks like tornado kick that not even jon jones would dream of throwing. muay thai uses much more practical striking.