Bits are always something that real confused me. Most people buy what they think is right, and what they can afford.
I use a colt correction on my horse with a medium port. We do western riding and she responds very well to it. I've been working on keeping gentle hands while using it and she doesn't resist. I was always confused on what bit to use for her, but my trainer recommended it, so I thought I'd give it a try. I feel that any bit can become harsh if you use it the wrong way. I've heard the colt correction is a very inhumane bit, but we use it on many of our horses and they ride fine with it.
I find bit fitting fascinating but I know it's confusing for many and the horse suffers if people are not informed. My suggestions would be to write more articles, with pictures, and a lot of testimonies from riders. What do they use, why, what were their challenges? How did they know the bit worked or didn't work??? Learning from others on their successes and failures sometimes is more valuable than just reading a informational piece of the functions of a bit or two. That's just a little "bit" of what I think. :)