I know this might be a touchy one to go on, but I myself prefer riding a horse without a bit. Not saying I won't ride a horse with a bit in but my horse responds much better without a bit and is clearly much happier. I will go as far as to say bits are cruel for horses because they are. 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. My view is that horses shouldn't have metal is their moths and unless they have been made numb to the head collar, all horses are better off without a bit. I say this having ridden my horse for almost 2 years struggling for an outline and as soon as we go bitless she works much happier and easiest. Being part Arab she will always struggle with a lot of more back end powered moves, yet it even helps with them too.
Just thought I'd also say those who ride on the bit, the bone on the bottom jaw is sharp and can cut flesh. When you pull that bit it pushes the gums into that very sharp bone, no matter the type of bit. Furthermore, those who ride in double jointed bits, when you pull that bit the joint jabs the top of the jaw, usually causing them to open their moths or put their tongue over the bit too soften the blow. In response we put a flash on, closing their moths meaning they cannot avoid the pain. Out of all the bits the rubber straight bar snaffle is what I'd say it's the softest.
I myself have done all these things with my horse before looking into it, watching youtube videos and learning a lot about it. I was able to borrow a bitless bridle which puts pressure on the poll and nose. I succeed a lot more in a bitless bridle and I feel all houses would given the chance with someone that knows what they're doing and makes them respond. I wont go as far too say that those who ride in bits shouldn't ride because that's not true. I think anyone who labels themselves a horseman or woman shouldn't rely on pain and bits to control their horses.
Of cause there are exceptions for everything I say so I'm not meaning to attack people, just expressing how I feel. Again, another thing with horses when used properly, it can bring out a fantastic result but the same can be achieved without a painful bit.