I purchased one from the beemer shop. I'm a big guy, 285 lbs. So obviously the factory was pretty inadequate.
I need to take the time to set my sag and try setting it up properly. But even with it just bolted on the way it arrived. It is night and day different from stock. I'm very happy with mine.
The 1600 bucks is a lot. But I already saved money buying a used Tenere. Any bike I buy will need setup for my weight.
BTW, I one day may setup the front forks for my weight. But for mostly aggressive road riding. I'm pretty happy with my current setup.