It's savagely quick of course. The 639hp 'S' model's 4.0-litre twin turbo V8 generates 900Nm of torque and gets to 62mph in just 3.2s en route to 196mph. At the top of the range, there's a 'Performance' version with 843hp that gets to 62mph in just 2.9s. The acceleration times assume you're using the provided 'RACE START' mode in the 9-speed SPEEDSHIFT MCT AMG auto gearbox, which comes with perfectly-sited steering wheel paddleshifters and software that blips the throttle on downshifts to the evocative accompaniment of popping and banging from the switchable AMG Performance exhaust system. What's even more impressive than the straight line speed though, is the way that the various chassis and drivetrain systems have been developed to interact in such a sophisticated manner. There are plenty of these, including torque vectoring and handling features developed specifically to improve the cornering stability and traction of this car, including an actively locking rear axle differential and rear wheel steering that turns the back wheels slightly in the same direction as the fronts at higher speeds.
Another thing you don't get on a GT 2-Door is this car's 4MATIC+ 4WD system, which usually channels drive to the rear wheels, with those at the front called into action on the occasions (which will be frequent if you're pushing on) when all that torque twist is too much for the rears to handle on their own. The 'S' variant also features an extra 'Drift' mode for track use that disconnects the clutch from the front wheels to allow for lurid, power-sliding circuit drifts. 'Drift Mode' only works in the most extreme setting that this model's incorporated 'AMG DYNAMIC SELECT' drive programme system can offer, a 'RACE' mode that's also exclusive to the 'S' variant as part of an 'AMG DYNAMIC PLUS' package that additionally includes dynamic engine mounts. The other selectable 'DYNAMIC SELECT' options - 'Comfort', 'Slippery', 'Sport' and 'Sport+' - are common to both GT 4-Door models and as you would expect, influence throttle response, gearshift timings, steering, exhaust note and stability settings. Plus they include integrated 'AMG DYNAMICS' handling programmes, which have a lot to do with this car's sublime chassis and drivetrain interaction. The balance here has clearly been chosen to favour track behaviour rather than ordinary urban or highway use. But this model is still an eminently usable commuting tool or trans-continental luxury GT when you need it to be.