He was the student of Grandmaster Kim...
Are you referring to Grandmaster Kyu Ha Kim based in PA?
I made a thread like this a while back, there is finally a place near me to take Taekwondo, and the price looks really good.
What do you guys think?

As has been mentioned, TKD is a striking art. That in and of itself carries many restrictions.
(At least our local) competitions were even more limited – no punches to the head, no leg sweeps, etc.
We learned some hand techniques – punches, palm strikes, blocks, but never got the chance to practice most of them.
I was in extremely good shape endurance and flexibility wise, and while I couldn’t build any muscle with all the cardio, I did get stronger and felt healthier.
For practical “real life” defense applications, you’re better off learning some grappling – Judo, JJ, Hapkido, etc.
I was fortunate that my one instructor – at the time a 3rd dan TKD – also studied Aikido – and would occasionally meet with me and several other students before class for free Aikido instruction.