What makes Schutzhund and PP dogs different are two fundamental things.
1. Stimulus
2. Environment
Schutzhund protection could be trained by using +R only. Its basics lays in using your dog's positive emotions on every step with totally friendly attitude to humans. A good Schutzhund dog is quite easy to recognize when he is still a young puppy by excessive playfulness, it is easy to make him ball mad. The training starts when the decoy plays war-of -tug with your puppy and you control him emotionally for doing right things holding the end of the lead. As long as training progresses and your dog matures, he learns to interact between you and the decoy, work under distractions and stay patient. The distractions (including stroking the dog on sides or on his head) are working as positive stimulus as well, nobody wants to cause pain to the dog. There are so called "good dogs" in Schutzhund, they are total optimists, always in a good mood during training, because they get what they want - their game. Schutzhund dogs don't protect anything, they prey on the sleeve and recognize the whole training session as a play when his mental stability is the most on the check, thus IPO illustrates nothing else but partnership. Though wearing a protective suit is a rule in Europe, it is absolutely unnecessary, a Schutzhund dog of 18 months would hesitate to bite flesh, and, if he did - he would be very confused. Agressive dogs are disqualified, because they take the whole issue too seriously as a real threat and could be dangerous to public in mid-training period.
Schutzhund dogs get used to certain environment. All dogs, in fact, aquire different attitudes to different environments and behave accordingly. An open field with a man, certain smells, sounds and presence of barking dogs set your dog's mind absolutely unmistakingly. Many Schutzhund trainers speculate what makes their dogs excited and how they possibly know where they would be taken, but somehow dogs expect their next visit to Schutzhund club and get agitated the day before the event (may be they know the week days).
Training PPD has different tasks. The dog should be able to protect you, not to play games. From the very beginning the puppy is irritated over food and toys, and should always win the battle with human. They are trained to recognize certain postures and human body language in order to recognise the threat, they should know, that human agression is not a joke. The dog should learn to fight for his life and not to be distracted by pain. There are many types of PP training, from simply training one dog to bite left hand (God knows what for) and chasing like in a police pursuit - to training two dogs to rip a human apart, biting different body parts on command, dealing with guns and knives. Some training methods of the latter could be very cruel to the dog. The environment must vary as much as possible, as well as the time of the day. Nobody trains a PP dog just for fun and your personal ambitions satisfaction like a Schutzhund dog, people train them to protect their dignity, their own life and lives of their family. Your PP dog becomes your weapon.