I know a guy who rode his horse in nothing but the Wonder Bit. . .simply because he liked the way his horse carried its head with that bit. Up high, with the nose tucked in. . .but the horse still didn't respect or respond to it. He couldn't even gait because he was so balled-up on himself all the time.
It created the "look" of a collected horse, but in truth that horse was so balled-up with energy and frustration that he would still occasionally "explode" when he found something to spook at.
A few years ago, the owner of that horse had a medical issue come up that required surgery, and he asked me to take his horse out on trail during the recovery period. He didn't care what bit or saddle I used, so I used my own, including a Robart's pinchless walking horse bit. Not saying that bit is the "magic button" for all horses, either, but it's what I had and I was curious to see how he'd go with the change.
The first part of our first ride was a little hairy, but after about a mile he settled down and was moving along relaxed and comfortable, at an easy gait. When my cell phone rang (something that normally would have triggered an "eruption" from the horse), he stopped and stood quietly on the trail while I took the call.
The owner of the horse later tried riding him with that bit. He said he "hated" it. I guess he just liked hauling on his horse's mouth the whole time. Whatever. . .his horse, his choice. I always felt bad for that horse after having been on him, though. He really did WANT to be a better horse. He was so relaxed and responsive on our rides.
I don't think the Wonder Bit in itself is a bad thing. . .it's a tool. If misused, it can create a disaster of a horse.
"Parelli horsemanship is just like painting by the numbers. You need absolutely no skill. You just put this color here and this color there, and when you're done, you have ... a mess no one wants." mp