We were testing the RS6 this afternoon at Silverstone and comparing it with the C63 Estate. The reason for the comparison was to question to the cost of the RS6 and see how close the much cheaper C63 could come to the RS6's capabilities.
They were both fitted with a Vbox, and Chris Harris set the lap times, then we ran them side-by-side along the Hangar Straight to compare their acceleration times.
One thing we discovered, which appears similar to the RS4 Avant which I recently sold, was that it seems the RS6 limits torque in the first few gears below certain revs. It's not a good car for a standing start, and despite switching off all the traction and stability controls it was just not playing ball with us. I am aware of this restriction within the RS4's standard mapping, so it looks like Audi have built the same profile into the RS6's.
The results of the comparison were not what we had expected, but I'll let you see for yourselves when we publish the videos and magazine feature.
I will be spending a few days in the RS6 later this week, before we hand it back to Audi.