My boy is a retired Dressage horse. He came to me in a Kimberwicke bit with a curb chain, and I was told to tighten the chain if he ran thru the bit. Say What???
And I rode him in it, with a loose curb the first season I had him.
The next year, I got a dr cooks bitless bridle off ebay
. It took about 15 minutes in the round pen to introduce him to the bridle, and we've used it ever since.
Honestly, I can't really tell much difference in the way he responds, and the bitless has just got to be more comfortable.