Dogs breeds were developed for a purpose. Depending on what you are going to do with a dog will determine what specific breed of dog you will want. In German Shepherds there are all kinds of different purpose dogs. If you want a protection dog, you will want one that will easily live and interact among the people in your life. If you want a sport dog, you are interested in a high drive intense dog. There are both kinds in every GS segment, ie Czech,DDR, American etc. Can they do both, yes sometimes, but it takes a knowledge of specific bloodlines and a large amount of training to make one of these. It disturbs me when people expect all these qualities to be packed in a puppy and think all they have to do is feed them and wait for it to materialize. Environment contributes the largest portion of who a dog is and what he will become. To blankly say that all Czech dogs are high drive and intense or that all DDR dogs are low drive is ignorant and unfair. There are both kinds in each bloodline. To make it simple, all dogs will bite, given the right circumstance, some quicker than others yes, but past environment will determine that response more than bloodlines. World class working dogs aren't born, they are made. It takes hundreds of hours of interaction and training to produce a world class dog. The ABILITY to learn and handle the pressure of such training is what is in the bloodlines. All bloodlines have such dogs. The breeder determines when he selects breeding crosses how much potential is going to be available in the progeny. This photo is a pic of my family dog in training. He is a calm, confident and "no bark" dog. He has never offered to do this in any other environment other than training. But it is reassuring to know that he has this in his arsenal should the need arise.