I have trained extensively with a makiwara, but it came through my study of karate not taekwondo. Please ignore my answers if they aren't applicable for your purposes.
- what is your technique (s) of movement
Not sure I understand the question, but I have trained a variety of strikes including punches, haito, shuto, and kicks. From my perspective, it's probably best used for building precision and focus with the seiken fist though.
- how many years have you trained with this tool
- how important do you think it is
Very important for karateka. For taekwondoin, I do wonder. Certainly I was never exposed to one in my initial study of TKD. We used heavy bags, focus mits, and kicking shields instead then.
- how much do you feel you have learned from using it
Tons. My sensei likes to say 'no makiwara, no punch'. It provides immediate feedback on every single punch. If you don't hit it right on with the knuckles, you will cut your skin badly. If your punch has no snap to it, the pushback from the post will tell you right away. If you're just pushing with your punch, the post will feel heavy on your fist. And of course, it helps you understand rather quickly the relationship between being grounded/rooted and striking hard.
- if you teach, do you teach it to your students
For my karate students, yes. It's considered a core training tool along with hojo undo exercises and of course Sanchin kata.
- if you have used it for many years, how as your approach to using the tool changed
I used to think of it as primarily a physical conditioning tool as a younger guy. Now I'm aware the mental focus it sharpens is just as important. I liked high repetitions because of the satisfying feedback the makiwara gives. Now I'm just as pleased if I can quickly step up and fire off 5 good punches. Obviously once you get to a certain level, it's more about staying honed and you don't need a lot of reps necessarily.
-Also, if you do the same training on a Powair style water filled heavy bag, no foam, just water right to the skin of the bag, how does it compare to the talyunbong?
Never used a "Powair".