In my experience with the Autobahn (Frankfurt <--> Munchen and around there), it's not typical to ride that fast for very long.
We had a little 1.3L Mini Cooper that maxed out at 170 km/h (105 mph) which was dead stable at that speed, and much more relaxed than any motorcycle. But we were being passed by the big BMW's, Audi's and Mercedes. In turn we passed nearly every motorcycle out there, lots of BMW's and Gold Wings going about 75mph capable of going much faster but they chose not to. I specifically recalled passed an R1, then a few minutes later he passed us like we were sitting still, and then we passed them again in a few miles.
There are speed limits on some sections, you will hit traffic that will slow you down, and other times the left-most lane will be too fast and the second-left-most-lane will be less than 100mph. 100mph is fast but there will be many cages eager to go faster and in the left-most-lane you'll be watching your mirrors when you should be watching what's in front. Unlike Nevada or the midwest we're not talking about long straight stretches highway with no traffic and no trees and no animals. It gets tiring when all your senses are notched up a bit, you're processing everything faster, wondering if the tires are dissipating heat fast enough, check your engine temp, additional neck strain and noise from the wind, etc.
While you don't have to worry about LEO's, there are lots of other factors. It is fun for a while exercising the bike and listening to the engine hum along and then it's nice to be going just a little slower and more relaxed and enjoying the trip. You'll eventually settle into a speed that's comfortable for you, your bike, and the environment, and I'm going to guess it's less than 100 mph.
I bet what's going to be more fun is where you're going to / from on the Autobahn. That's where you'll enjoy not having a heavy top-case to affect your front tire grip. This is the main reason to load all the heavy stuff on your pillion seat, or better yet in your tankbag.
