That's not to say that it's terrible to drive. We favour the lighter normal steering mode over the artificially heavy Dynamic mode, and the RS6 scythes through broad, sweeping curves in a satisfyingly fluid, meticulously neutral fashion. But there's little or no finesse to the way it goes about anything more complex or demanding than that; a Jaguar XJR or the outgoing Mercedes E63 AMG both have more subtlety and poise to their handlin, which makes them feel more engaging and responsive.
That's not our only gripe. Again, on the optional suspension, ride comfort in Dynamic mode is pretty woeful, with wince-inducing short-sprung vertical damper movements that never let the car or passengers rest. At least in the softer modes it calms down a bit, and the trade you make in more noticeable body roll is an easy one to take in favour of the more forgiving bump absorption and generally more settled ride comfort, although this always feels like a firm car that's working hard to keep a lot of weight in check.
Now to what the RS6 does well: speed. And lots of it. Good grief, the RS6 is ludicrous. Can you feel the difference between the Performance and the standard car? It's been a while since we unleashed a standard RS6 in the UK, but honestly you'd struggle to tell. The extra mid-range grunt is always going to be more telling than the outright top-end performance, so maybe there's a fraction more ballistic response when you're riding the overboost function, but the over-indulgence of pace is there to scramble your insides in either version of the RS6. There's no launch function, so just standing on the throttle is all it takes to experience the full madness of a car of this size stropping up to 62mph from rest in 3.7sec. The four-wheel drive system means you get virtually no slip away from the line even in poor conditions, and from there on you can enjoy the impressively flexible, stupidly potent power delivery offered by this rather joyous twin-turbo V8. It sounds great and it is brilliant fun to use in all sorts of situations, helped by the smooth-shifting eight-speed Tiptronic automatic gearbox.
Our car also came with carbon-ceramic brakes, which are a £9375 option, and while we didn't take the car on track and therefore didn't get to test their resistance to fade, they do offer decent pedal feel in all sorts of road use once you've got used to their sharp initial response.
Otherwise, the wide tyres kick up plenty of noise but it's not bothersome enough to intrude on your consciousness unless you hit a really coarse surface, and, engine aside, the RS6 Avant remains, of course, a really decent big family estate that you can use every day - just like any other A6 estate. You get just about everything as standard including blue-woven carbonfibre inlay and diamond-stitched leather and Alcantara sports seats (which will cosset and hold in place virtually any shape of driver), on top of the adaptive LED headlights and full complement of audio, multimedia and driver aids. It's expensive, but you don't need to add anything.