My GSD has always been this way as well, and I appreciate it, because at our dog park, the small dogs always come on our side. He's 8 months old, but won't play rough or run/chase with a small dog (less than 15lbs ish). He can and has held his own with bigger rougher dogs though, don't worry. He's just a gentleman.

However, his puppy skills are lacking. He'll try to play VERY rough with any sized puppy. It's only adult small dogs he's good with.
