I have earned two black belts. One in a traditional system of taekwondo and one in the modern sports style of TKD. I know that it is possible for a gifted student to earn their bb in 3 years in each system according to both of my teachers. However, noone at either of the two schools ever has. At an average it takes 4 years+ to earn a black belt.
I earned my first bb in 4+ years, I round it up four. We had heavy emphasis on kata, self defense, and step sparring. I trained 5x's a week sometimes for three hours and sometimes for two hours a day. Every once in a while I would attend saturday classes for extreme workouts two hours non stop.
We did kata from 4 systems of korean karate: Pyung, taegueks, chon hon, pal gwe, and kee cho sets.+impromptu kata, +weapons kata, +musical kata. So we had arond 43-45 katas to do for a bb test. The last three were not self defense based but performance based.
The classes were two hour long and on average we spent 1 hour on kata alone.
We did not do bunkai in the sense that the techniques pulled for self defense applications were not taken from the exact sequence in which they were in the kata, instead we had a seperate set of sequences set up for each scenerio of attack. So if your wondering about our tuite (grappling) training, that would be out of a judo/jujutsu. It woud look nothing like the katas. Only the striking portion of step sparring looked like kata and even those were not in the same sequence as the kata. So as you can see from my experience with kata and the way I was taught self defense I have really no appreciation for kata.
We took the time to use nearly all the empty hand strikes found in karate/taekwondo, strikes for specific points of the bod, something I feel is seriously lacking in todays korean karate, were mainly the fist is used and the othre strikes ignored.
My second school, which is more sports based, we only do one set of kata, 9 kata for a black belt. Some step sparring, lots of step sparring for sport. Heavy emphasis on sparring, foot work for sparring, bag drills for power, padle drills for reaction time, judging distance, endless sparring combinations, and sparring strategy. Three years to earn a black belt however, there is a higher level of skil require for bb, so it has taken students 5-7 years to earn a bb. Here kata is only practiced as formailty for testing, however, it is practiced so that balance and power is very well developed incase the student wishes to enter kata competition. Literally no application is taught from the kata, if y chance your school teaches self defense, ten most likely it would be from hapkido or jujutsu. No weapons taught at this school, strictly competition based.
"Poor is the pupil who
does not surpass his
master" - Leonardo Da