S.L.
I've trained dogs for as long as I can remember. I handle a search and rescue dog that I rescued from a local shelter. He is a therapy dog as well. I'm saying this just so you know I do know what I'm talking about (at least I think I do). :)
Please keep in mind that any dog of any breed can bite with little to no warning. If you have little ones at home, you should think about if a dog does snap suddenly, where will his bite land? Most med to big dogs are face-level with toddlers. Never ever leave a dog alone in a room with a small child.
My SAR/Therapy dog is a golden retriever. He is a wonderful family dog. I adopted him at about 11-months. He was already obedience trained and very gentle. You can find great dogs at the shelters if you are willing to wait for the right one to come along. Older dogs are usually better. They are calmer and often come already housetrained. Even goldens are often very active as puppies.