HOWEVER, I do still think less contact on a stronger bit rather than permanently pulling a horse on a short bit or bit less is better
Bits are cruel. They may not cause the moths to bleed because they do a lot of damage underneath to the flesh. A bigger bit that doesn't have to be touched is better. Just think though, what if you fall of on a hack or a trail and your horse bolts. When they stop they'll probably eat some grass, the reins slip and they stand on it, Lucy their head and instead of taking their time to think and take the pressure off by moving their for, they panic and pull against it more. Those situations are when horses get badly hurt. And I don't know whether Western competitions allow bitless, pretty sure they do bit every single British one let's bitless riders compete.
If you are willing to put the time in to train a horse to ride in a bit so responsively why not spend that time on not putting a bit in their mouths.
Everyone seems to just read the bit they don't like about my post and then reply but I said all horses are different and work in didn't ways. If a horse leafs well and doesn't evade the head collar then they will ride bitless just as well. The responsive they are on the ground the less you use your lead rope, right? Same goes for riding if you're willing to put the time and effort in to train the with a bit, try putting the same time and effort without a bit.
Of cause no-one ever will because bits are too strongly placed in the equine world when they shouldn't be. Horses are not designed to have anything but food and water in their mouths.
I do ride others horses in bits and don't get me wrong, they work well but they would work just as well or better without a bit.
Also, my horse was just an example, I know many horses I have backed and trained that work better bitless.
I hadn't really looked up on the straight bar but just from looking at it I'd say it's the kindest, but I don't know much about that.
Again, all horses are different and given the chance I still think MOST would work much happier without a chunk of metal in their moths. Also, most horses I have known to finish their career in showjumping, barrel racing and other fast working competitions have permanently bruised mouths. Not saying you do that to your house, but people get bruises from leaning on their legs for too long and bits are known, even when not doing anything, to making their tongues go numb and can take hours to get the feel back. Everything about bits are not designed for the comfort of the horse.
Whether someone chooses to take advantage of the fact they can use pain to control them takes bits into a whole new level of pain. Those who ride in an outline and have contact will make mistakes like being left behind and even if you let the reins slip, that's still going to hurt.
Again everything is only as painful as you make it but bits make it easier to cause pain.