I think wether or not a horse is well trained or not depends as much on the training level of the rider as it does the horse. If I were to buy a great dressage horse, I would probably mess him up with my lack of knowledge and ability. What I have is what I consider to be a very good trail horse, but I bet a lot of you would think him an ill trained plug. He will go, move over out of the rode, and speed up with my legs and seat...he knows the verbal command whoa and easy (you know like when you are going through rough terrain that you want them to tiptoe through), he knows walk, running walk and canter (although that can be a bit flighty), he is road safe, he leads well and will come to me in the pasture. He may know more than that, but I wouldn't know it if he does, because I don't. So in my book, yes he is a well trained trail horse. He doesn't collect, or isn't always on the correct lead (at least I don't think he is...but I wouldn't really know
), he is nervous around men (even the farrier) and has had some general trust issues and I even had to send him to a trainer to learn to be mounted without panicking and standing still. He's not perfect, but he is a really good fit for me and what I want him to do.