Small does not equal less in GSDs. Quicker, less prone to joint issues and live longer(in theory). There is a reason BCs are cheater dogs in flyball, they are just about perfectly sized for quickness and speed. That and their insane drive. I have two smaller GSDs now(female is tiny) and I have as much fun with them as my dearly departed mutant giant Banjo. They are still GSD, and attitude and disposition make up 99% of what makes dogs special anyways. Eat less too....
Never cook bacon while naked.