I had a one for a day at the BMW School - surprisingly different to a regular boxer:
- The engine is way more revvie, meaning it wants to be on the power more, which is great fun when the conditions allow, which also means that it has less of the tractor like capabilities of the regular boxer... you can't just leave it in second and let the torque pull you through those technical section
- This compounded by the traction control - at speed and particularly for fast, steep hill climbs, it's really quite something. But in deep muddy, rocky sections - I found it pretty hard to get going... Although I think that might just be a practice thing...
- The ABS is like some kind of voodoo! On one really quite steep and rocky descent, the guide said just grab and handful and let the bike work it out... and it did. Handled the drop offs, mud and slippery rocks without issue. It honestly felt like cheating.
There were six of us in our group, pushing on at a pretty good pace, with a few falls - and no one managed to break the bike in the day.
As others have said - go to the school - you can now do what they call 'Development Days' which are one day rides, grouped in to people of similar ability, with limited instruction, mostly riding.