I saw them perform at a local show recently and I thought they were really shite tbh. The horses are meant to be trained using natural horsemanship methods, but all I saw were three horses in socking great curb bits (and the horses had their mouths open in obvious discomfort whenever there was pressure put on the reins) and standing martingales that looked too tight, and the riders needed schooling whips to get them to do anything.
I was also unimpressed that one of the 'expert' riders was riding in shoes with no heel, and her lower leg position was so far forward that her toe was practically sticking out in front of her horse's shoulder. Also, there were attempts at half pass, passage, canter pirouette which were the worst I've ever seen and the riders seemed to have no idea of being on the correct canter lead or diagonal when riding fairly tight circles.
What does everyone else think?