It's almost impossible to fault the Audi's V8 engine, though. Once the RS7 gets off the line - and the revs climb over 2000 - it pulls hard to the redline. Throttle response is crisp and vivid, and with the optional sports exhaust in Dynamic mode there's plenty of aural theatre.
Just off idle the RS7 emits a low, baritone note reminiscent of a larger displacement AMG, and an aggressive roar permeates the cabin through the rev range. Step off the throttle, even at lower speeds, and you'll be serenaded with pops, bangs and crackles, evoking memories of the UR-Quattro. It's a very vibrant, capable and gratifying powerplant. Audi's cylinder-on-demand system also functions entirely unobtrusively, with no noticeable effect on how the car drives.
The eight-speed tiptronic transmission proves adept at quietly and smoothly shifting through each of its ratios, when left to its own devices. In either Sport or Normal mode it does a very good job of picking the right gear, and in manual mode it's satisfying to see that you can fling the engine against the limiter with abandon - it won't override you and shift up. The catch is, unfortunately, that it can be a little reluctant to change up or down when you want it to.
Consequently you're left either having to increase your braking effort in a corner, or bouncing noisily and slightly embarrassingly against the limiter as you attempt to make a swift overtake.