Do haltis and gentle leaders TEACH a dog proper leash behavior?

To me they are more of a control device. I think that the dog learns not to pull against them but they don't learn not to pull against a collar. However it could be that I have never seen dogs that were properly trained using these devices but rather dragged around on them. I have always felt that if you want your dog to learn to walk on a loose leash and collar, than a collar and leash should be used for the training. I've always had a difficult time getting dogs to accept wearing head collars. It seems like they are always fighting them.