I decided to try 'bitless' on my horse after I jumped on bareback one day with just a halter and lead. He responded amazingly to my one rein stops, which he had almost always ignored when bitted.
The next day I attached the reins to his halter, and he is a different horse. In the past he was a school horse and I wouldn't be surprised if he has a bad mouth as a result, especially since he tends to gape to avoid bit contact. With the halter, he turns on a dime, stops on command, backs up (which he does very reluctantly when bitted), and really pays attention. I rode him in a bit again the other day, and it was a fight the entire time.
Whilst I could continue riding in his halter, I am going to invest in a rope riding halter A) because I can B) because his halter isn't exactly high quality, and the thought of it breaking during a ride is worrying and C) because the reins sit really oddly. Plus, it's annoying to have to attach the reins for every ride. I'll also get the added benefit of pressure points from the knots, just to give a little extra control.