A well-bred and very well-trained GSD is amazing. However, most people who own them have no goddamn business owning them, or obtained a poorly bred one. Well over half of the GSDs I see are neurotic and aggressive as fuck to either other dogs or people, sometimes both. If a dog is ever marked as a "major caution - owner needs to muzzle" it is almost always going to be a GSD.
So, great dogs in an ideal situation, but you have to be careful.