Yeah buddy, I have the same tires and the same noise. Cupping the tread as well, so I need new shocks. The local Mercedes Dealer suspension expert said not to put anything on the car but Michellins. The Pilot Plus tires are my next set.
Took the car into a frame shop to see what they could find regarding uneven tire wear. Turns out the front wheel bearings were shot. Just 24K miles too. I think someone missed the wheel bearing check when the dealer certified the car. Anyway, I have an extended service plan for $2200. The new bearings and hubs cost $1200, so I'm doing all right. I have the disappearing deductible plan so it's like my original warranty never went away. It will probably pay for itself my next time in!
I'm putting the adjustable KONIs on the front soon. There're the yellow ones at the KONI website.
Later days . . .