In a few short months, Cody has already reached the milestone of being a reliable general riding horse.
Nancy is riding him regularly now and I have put novice riders on him to give lessons. While I am the only one cantering him at the moment, he is perfectly trustworthy at the walk and trot for anyone. His response to leg pressure and changes in seat are better than most horses I have ridden after a much greater period of time in training, as he has picked up this part of this training at a remarkable rate. All he really needs now is time under saddle, carrying a rider, to develop his balance to the point that it becomes as natural for him as the lesser gaits are currently.
Mentally he has proven to be just a steady as we first believed. Not just smart and a quick study, but also brave and confident. His response to new, potentially frightening things, is to stop and look for several seconds, mulling it over, then he just moves on. As long as you give him the short time he needs to process, you can pretty much count on him getting past it and never having the same issue again. Nancy says this particular trait has allowed her to come to trust this young horse very quickly.
I believe another trait that has helped Nancy form a trust bond with him is the fact that he has never come close to bucking or similar behavior. Even when pushed to do things that put his balance at risk, he has never reacted adversely. Instead he just keeps plugging away as he is told, apparently willing to trust the rider not to let him get hurt. As long as we never betray this trust, I predict his meteoric rise toward finished warhorse to continue.