great dogs. Just make sure you do train them and interact them with people and other dogs. Do obedience class as a pup, and go through as far as you can. Interaction with people and other dogs is huge with any dog, but its very important with dogs that are big and strong, such as GSDs.
Some people get lucky and dont train/interact their dogs and end great with people and dogs, and others arent so lucky. Granted, it can still happen even with good interaction while young.
Watch for warning signs as a pup. ANYTHING that may be a sign of dominance/aggression (even if its "just a puppy being a puppy") can lead to horrible habits and dominance when older, and then you're in trouble. Food guarding, humping, even something as simple and seemingly harmless as the puppy batting your hands with its paws while you're rubbing its belly is a dominant trait that needs to be dealt with.
good luck, i love dogs.