My "ship came in" today and I'm having the Performance Power Kit, Performance Exhaust (and the short shifter too) installed at the Port Hueneme VPC.
I did put 1264 miles on it during my Euro Delivery, but it will be hard for me to offer before/after impressions.... since I was following break-in and I had an extra 300 lbs (passenger + luggage) with me. I can provide a comparison to my stock C63 though
I should take possession in a week or two. I'm expecting it to feel like a little rocket!