I've been fortunate enough to drive on the autobahn network in Germany and it is indeed a great place to drive. Despite the unrestricted sections it can still be tricky to hit high speeds in many areas because of traffic or road conditions. Regardless it's nice to be able to pass slower traffic at a speed one judges acceptable without always watching out for a patrol car waiting to pull one over.
Back before the 2000s Montana was a place of legend (along with Germany) because of their "reasonable and prudent" speed standard. Too bad that is gone. Interestingly going from "reasonable and prudent" to a specified speed limit may have made Montana roads less safe.
RE: Need for speed. Germany is the place.