...However in my 20+years of doing this I have always had the best luck with a simple german silver loose ring "beanie" bit on a horse with a sensitive mouth.
Must be nice to have a bit that works for darn near every horse. I've only got 3 horses, and 2 of them don't care much about what bit is used. One is picky. Maybe Mia is a 1 in 100 horse that is fussy. I don't know about all horses. I'm just reporting what I've seen with my horses.
Regarding double reins with a 3 ring gag. Think about the action that bit has. By only having one rein on the leverage rings on the bit you are constantly applying leverage action with no break for the horse.
If I rode with constant contact, that might be true. I don't. We mostly ride together with slack in the reins.
Having a snaffle rein with the leverage rein you are offering the horse a break from the heavy action the leverage causes. If you have a horse that has had a bad experience with a heavier bit and hard hands you are going make the horse panic before it even has a chance to accept the bit. When you are taking a horse back to learning to accept a new bit you do not want to apply heavy pressure on them. You want something light, soft and gentle. Give the horse a chance to soften up and realize that the bit is not the be all and end all...
Mia was started in a full cheek snaffle. We also rode about 3 years bitless. Leverage bits are also not about heavy pressure. Bits are about communicating, not punishing. That is why I think each horse needs to be thought about on an individual basis instead of saying one bit is milder than another bit. What works for Mia is not what I use for Trooper.
My mare will go over backwards on you if you touch her mouth with more then a soft "yes I am here". Last summer when I was doing jumpers with her she was getting strong. I put a 3 ring gag(dutch) and before I even got on her she was in a panic. So I put a french link full cheek and she was good to go and happy as can be.
There has never been at any one point that anyone has said one type of bit works for every horse. However there is one style of bit that works best for soft sensitive horses. Not one bit. One style of bit. BIG difference.
I didn't criticize your choice of bit. Nor your choice of STYLE of bit. I can easily see how an elevator or gag bit would make some horses panic. I can see how a Waterford would not work with some horses. I've tried a western curb bit with Mia...worked well one ride, but I think both of us felt it was kind of strange. I may work with her over time to teach her how to respond to a western curb, or maybe not.
My main point was to think about the choices as an integrated whole. It isn't all about the mouthpiece. It is also about the shape of the mouth, the training and previous experience, how the bit interacts with the bridle, how the sides interact with the horse's lips, etc. And the rider's hands.
You couldn't pay me enough to use a spade bit with Mia. Neither Mia nor I have ANY business with one. But with the right training, and with the right person, horses do well in spade bits.
When I stopped riding bitless, I was still thinking that bits were about inflicting pain, and how could I avoid inflicting pain. Mia has taught me that bits are about communication, and how a horse understands the various pressures. They get a vote.
bsms, I take my boys' choice into consideration very seriously. If not for him, I would have continued riding in a rope halter, but his attitude showed that he dislikes it if I try to ask for something more than turning and stopping...then I tried out an S hackamore, although it was in a way "bitting up" - just bitless. And all of a sudden he is again willing, soft and a happy camper, and we've progressed very much since we started using the S hackamore...If he hates something - he shows it loud and clear, so I don't think that I just supressed him with the leverage action of a hack - he'd protest, which he never did. So I will listen and observe him closely
I agree. When I first walked along side Mia and watched the action of the elevator bit in her mouth, I thought she would hate it. But she seems happy with it. I thought a 3-piece snaffle would be the cat's meow for her, but she doesn't like them. I don't know why. But it is nice to have a horse who communicates her opinions. If Trooper disliked a bit, I'm not sure he would ever show it. He's more of the suffer in silence type.