I currently use the Robart's "pinchless" Walking Horse bit. It's very similar to the one marketed and sold by Brenda Imus' "Gaits of Gold" but significantly less expensive and (IMO) actually a better design, using better-quality materials.
The horses I've ridden in the Robart's (TWHs) have done very well in it. One of them is my own "old reliable" trail buddy, a 12 year old TWH I've owned since he was three. The other horses, two in particular, often got very tense on trail. One was being ridden in a "Wonder Bit," the other was going in a double-twisted wire TWH bit.
It was like a vicious circle with those bits, because if the horse got tense, the rider got nervous and took up more slack in anticipation of the horse having a "blow-up." That would make the horse even more anxious, until it was just a prancing ball of energy.
I've taken both horses out on trail (with other horses, and on their own) in the Robart's bit and they seem very relaxed and "happy" with it. . .while still being responsive to cues. I love the independently-moving sides and the "pinchless" feature in the corners of the mouth.
As it often happens, when a trainer puts their name on a piece of equipment, the price jumps of the item significantly. I bought the Robart's bit last year after the Imus bit I'd owned for just a couple of years began breaking apart in the mouthpiece. While there have supposedly been "improvements" made to the Imus bit, it still costs about $30 more than the Robart's. . .personally, after the negative experience I had with the Imus product (and their customer service), I'll just stick to the Robart's.