I dont use either. . they aren't HORRIBLE when they're used correctly, but it seems like a band-aid to me. I would not go to a trainer that forces you to use prong or choke chains . . she sounds really annoying and uneducated. Basically, she probably want everyone to put chokers on their dogs to make her job easier! In the long-run, training with a flat or rolled leather collar means youre voice and body language controls the dog, not a pinching or throat-restricting collar. Our trainers are the opposite, they don't allow prong collar, chokers, haltis or harnesses in class. . and all of the dogs that are past the first three or four classes never act up, pull, run away, or ignore their owners, they're all really good pups without anything but rolled/flat leather collars.