Thank you Smrobs...very useful post
It's funny, because I tried a mild curb on my mare this morning, and she didn't seem to care for it at all...she was tense, and 'hyped' up. I don't know if it has anything to do with how she was ridden prior to me acquiring her, but definitely confirmed to me that she is not ready for one yet, either. She responds very well in a French Link Full cheek, and I've been riding her lately in a D-Ring, and she likes that too. Now if this was 10 years ago, I probably would have wigged out, and thought OMG she needs a harsher bit...now on the contrary, I feel a horse needs to go back down to a snaffle when they aren't responsive to a curb. Funny how time, and education teach you much needed stuff.