Nice post, thanks for taking the time.
I agree, its all training not the bit, but sometime conventional methods just won't get it. Until my current mare, which I got as a filly, I never had any problems with other horses not responding to a bit, but she just walked right through them. She did beautifully and what was asked at everything else, just not "whoa". I am not willing to put extreme pressure on a horse's mouth, or see-saw it to death so I would have to turn her to get her to stop. I went through 3 snaffles, and a waterford - and miles of "backing up".
I worked and worked to get her to "get" that when I pick up the reins, all four feet need to come to a halt in two steps...not looking for a reining stop here! She seemed to respond to the french link the best, but not entirely. It was sooo frustrating. I decided there was some sort of "disconnect", so I trained her on the ground at liberty to stop cold when I said "halt". I applied this in the saddle simultaneousely w the reins and seat. It worked! I am still using the french link. I will never know what the trouble was.
But I will say this - I don't like the thought of putting any sort of metal in my horses mouth that says "made in china".