My uncle has a Brittany he uses for hunting. VERY energetic dog! Always moving, always ready to go. Even when sleeping, this dog looks like he's ready to jump up at a moment's notice. He's also very smart, sweet and an awesome frisbee dog. He's also great with kids.
But I wouldn't recommend these dogs to anyone who's not ready to deal with an insane amount of energy. Like any high-energy dog, if you don't provide enough of an energy outlet, they can develop destructive habits and possibly other behavior issues.