Awesome information but before this thread gets moved, I have a quick question. I too ride with a Tom Thumb, only because that's what my horse's previous owner rode with. But I don't think it's the best for my horse now and what I do.
I ride with both hands when I'm excercising/schooling on the property, but when I hit the trails I ride with one hand, on a loose rein. I've been interested in a 'western dressage' program that is starting up in my area, so I ride with more contact then I used to. Because of this, I'm trying to find a good, all around bit for this kind of work, and one that I can use on the trails as well. I've never really been happy with the Tom Thumb...just couldn't come up with a good alternative. And my horse is a 9 year old well broke gelding, who has been very forgiving of the TT.