I have a German Shepherd who is the most loyal, protective, intelligent, loving dog I have ever owned. I got her after a neighbor kept stealing from me. It worked because I can now leave the doors unlocked. She has that growl that scares the bejeezus out of strangers too. She is a very good judge of character. I do have to stay on top of her so she remembers her place because if I don't she thinks she's the queen.
I also have a 90 pound yellow lab who is the goofiest dog in the world. Someone dumped her off as a puppy and she looked me in the eye and is now part of the family. She's the typical stubborn, mouthy lab. She has eaten the coffee table, if anything is in reach of her mouth it's fair game, she steals everything and sneaks it outside. She's a social dog and if she can get out of the fence she runs immediately to my neighbor who hates dogs and gives him a big lick.
I haven't had a dog since I was a little kid, so this will be quite an experience for me. We expect the shepherds will not only be loyal companions, but be first line of defense for the house. If anybody makes it past the dogs, well, both my husband and I shoot.