I am curious about the exhaust timing also. I have not played with mine yet.
I do want to point out that the intake cam adjuster should be set up to be on through out the rpm range. Mine flows significantly better with it on. I made over 50rwhp with it on vs with it off. The curves were almost identical. I have been playing with it recently and even at 5000rpm I still flow more and make more power with the intake cam advance on. It seems to fade off a little after that but not much difference with it on or off at 6000rpm which is were I shift.
In my opinion I think that Mercedes does everything for low to mid range torque as Jay was saying. So improving high rpm power is the key at a certain point. My car for instance falls on its face at above 5200rpm, which is why I need to do exhaust.