Personally, I will never put anything without a smooth mouthpiece in my horses mouths.
Why? I just think it is unnecessary. There are plenty of bits out there that have more 'bite', more leverage, more strength, but still have a smooth mouthpiece that is comfortable for the horse to carry and play with when i'm not touching the reins. There are thinner bits, thicker bits, leverage bits, gag bits, ported bits, so on and so forth. I just don't see the need to use something that I don't see as comfortable for the horse to carry.
Here's the deal, he has been hanging on my hands, and ignoring the aids to slow him down, so we have put this in his mouth. He doesn't seemto care, doesn't make a big deal out of it or anything. The weird thing is, after going from such a simple bit to this, I have noticed NO difference. Is this weird/bad?
Not so weird the way I see it. The new bit has zero difference in action to the old one - The only thing that has changed is the texture. It still performs in the exact same way. He may have thick gums and a not-so-sensitive mouth, and may have simply not even noticed the change in texture!
Don't know if you want thoughts or not, but if you want a change, then you need to change something - And in my view, just changing the texture of the mouthpiece won't do much other than maybe making him uncomfortable.
He may go better and lighten up in a bit with a bit of gag action or a bit of curb action - Are you english or western? English you could try a kimberwick - A small amount of curb action, or a snaffle with hooks - A small amount of gag action.