"I see people living in downtown Atlanta loft apartments with huge dogs - mastiffs and Great Danes"
I've owned both mastiffs and great danes. They were completely inside dogs. Both make wonderful apartment dogs. They have the metabolism of a rock. A short walk once a day is all it takes to make them happy. A typical day is move from the couch to the love seat. Take a nap. Move from the love seat to the bed. Take a nap. Move from the bed to the couch. Take a nap. Repeat.
BTW, they make wonderful afternoon nap buddies. They are experts at afternoon naps.
I have a friend that has a great dane. Exactly like you described. Isn't it funny how people get hung up on the size of an animal?
My Labs are field line (one on site, one coming Wednesday!) and they are most definitely NOT.
"Afternoon nap? What's that? Why are you lying there when there are squirrels to chase and doves to bark at? Here, let me help you off the sofa!" < tug, tug, tug, bark, bark, bark >