I've known people who use the "Wonder Bit" exclusively on their horses, as some kind of cure-all.
In one case, a guy bought the horse as a two year old and continued to ride it in the Wonder Bit until it was eight. Had a bad case of colic earlier this year and didn't make it through.
It was a really nice TWH gelding. . .big, black, beautiful expression, long forelock and mane. Couldn't gait worth a lick, though, because the rider was always keeping it on a tight rein and didn't have a clue what a TWH was supposed to move like. The horse moved in a hard pace any time it was allowed to go faster than a dog-walk.
I guess he also thought it looked good to have a horse with the proudly arched neck and tucked chin. That horse was so keyed-up all the time. . .like a rubber band stretched as far as it would go. . .and sometimes he'd just snap. Honestly, I think the guy just wanted it that way. . .he was one of those people who liked to show what a "great rider" he was because he was on such a "wild" horse and still able to control it.
He never tried to move into anything less severe because the Wonder Bit "works."
I did have the chance to ride that horse a few times on my own, out on trail. I used a Robart's pinchless Walking Horse bit, and although the horse had long since lost the muscle memory to gait well, he was so easy and relaxed and still very responsive. We went out for several hours at a time, by ourselves, and never had an issue with a spook, bold, "snap," or other issue. Turns out, it really was a really nice horse with a beautiful temperament and a really stoopid owner.
When I told the owner how well the horse liked the other bit, he refused to listen because "the Wonder Bit is what he was trained in, so there's no reason to change that." I think he may have tried my bit once and claimed it "didn't work" and he hated it, so he went back to the Wonder Bit.
Not saying the bit itself is "bad," but I would question why someone continues to ride their horse in one.
Please copy and paste this to your signature if you know someone, or have been affected by someone who needs a smack upside the head. Lets raise awareness.