Ah yes, but Annette, you are a GSD EXPERT! and the GSDs know that (and thus defer to you) !
My two dogs can play rough together, and to me, it is nothing, but can't tell you how many people freak out at a bit of crazyness from those two!
It is amazing how vicious dogs can look when they play.
I fully understand your concern. As an example, many border collies annoy other dogs because of their constant need to herd them. I have seen dogs snap at border collies simply because they resented *the stare.*
Herding dogs have a special working temperament. They do need to gain and maintain control. Within all populations there are exceptions to the rule...a dog who may not exhibit characteristics of the breed as much as others. Or lines where such characteristics or behaviors are not emphasized.
I feel that there is likely a breeder out there who emphasizes companion dogs over dogs with a high prey drive. If I can find one mellow border collie, there is possibly a mellow GSD in my future!!!!