Try the 507, handling and power delivery will make your eyes bleed
I had a couple of Merc diesels and no doubt they are fast and capable but once you have actually driven the V8 AMG you will soon understand.
The 507 has a massive power band and puts it's power down so well, mid range torque in real world side by side with a C350 is night and day.
Look up Rebellion they tuned a C350 with outstanding results and also ran it at the VMAX event but it showed the real world performance compared to C63's.
I would have another Merc diesel any day as they are perfect for every day but I'm going thorough the AMG phase right now
