I think this 100% depends on the needs of the dog. We can generalize all day and say you can do (enter lifestyle here) with GSDs and get away with it. In that vein, you will find plenty of people who say, "oh sure. we work full time and our GSD is fine with whatever."
However, when getting a puppy, you simply do not know. If this is the route you want to go, try looking into a rescue first. The foster parents can tell you what the dog requires in terms of exercise, attention, etc.
Try this scenario...you get a puppy who requires a lot of exercise. You get home after an 11 hour workday. You want to relax, put your feet up make dinner, watch the news.....but Fido needs to run. He's got 11 hours of puppy energy built up. You have to take him out for his run (whether its a leash walk/run, chasing a ball, whatever).
McCoy is 3 and still has the energy of a puppy. I recently got him involved in Daycare. I love it, he loves it, win/win. The cost does add up, though.
Explore the possibility of a rescue before you make a decision.