Hey Monkey,
I've never ridden in Germany, but I did spend 3 weeks there last summer. Roads are great, although up around Hatz (sp?) near the old East/West border there are some roads closed to Motorrad on weekends. This is because there are so many crashes.
I also had a German mate, who went back for a holiday who said the roads around Garmisch Partkirken (sp?) in Bavaria, near Neushwanstein are magic, although they were so good he overcooked it and woke up in hospital with a ruptured spleen among other things.
You may need to check the areas you are going have roads open to Motorcycles on weekends.
Hopefully someone more local can answer in more detail
Mick