I have very light hands--I pride myself on this--and I will not be using my reins for balance. A shanked bit will not be used harshly or inappropriately.
Previous owner/trainer suggests a Reinsman Jr. Cow Horse bit (three piece mouth). I have only ridden the horse once and she did nicely in the regular snaffle but, this was at a walk/trot and I hope to move up to some cattle work at some point and would like a little more control in those instances. (I would probably switch between the snaffle and the 'new' bit for trail rides vs. working.) If she continues to behave as well as she did then she won't have to know which bit is in her mouth at all, ha ha. Also, I prefer the look of a fancier bit...call me vain. :)