On a track, things are much easier. No worries about traffic, no pre-emptive thinking necessary (at least not too much), no worries about loosing control/drifting, etc.

Track is a kiddy place but I agree that it is much safer and much more suitable to learn about a car's true limitations. You can't drive at the limit on a public road, this wouldn't only be insane but also very dangerous.

Hockenheim would be just right (like you suggested in an earlier post), the Nordschleife favors powerful cars, Hockenheim good drivers.