AMG has created a remarkable all-rounder with performance to shock, a soundtrack to awe and agility to surprise. The lack of steering feel and delayed gearbox response frustrate, but accept this and few cars offer such a complete package.

When it comes to very fast Mercedes drop-tops, it’s hard to argue there’s a need for anything above the very rapid SL500. AMG begs to differ, though – and has created a monster in the process.

Ignore the 63 badge on the bootlid, as under the SL63 AMG’s bonnet is a 5.5-litre V8, with a pair of turbochargers helping  it produce huge power. In the standard car, that’s 503bhp, but our test car had a 27bhp boost to 530bhp, thanks to the optional Performance Pack.

Yet it’s torque, not power, that’s the most impressive thing about this engine: the Performance Pack sees the figure top 900Nm. That’s enough to trouble the rear tyres and traction control while helping the SL63 accelerate from 0-62mph in only 4.2 seconds.

Keep your foot to the floor  and it’ll manage 125mph in just 12.6 seconds. The Performance Pack then allows it to sail past  the usual 155mph electronic  limiter, all the way to 186mph.

In the unlikely event that such staggering speed isn’t addictive enough, the engine and exhaust notes will captivate and thrill you. The V8 sounds fantastic and the  burbling, crackling exhausts only add to the drama – even more  so with the roof folded down.

So this car is as quick and noisy as a dragster in a straight line, but it doesn’t lack handling ability thanks to quick and alert AMG-tuned steering. There’s not much in the way of feel, though. This makes it difficult to judge the limit of grip – although it’s so high, you’re unlikely to reach it on a public road. And while the AMG obviously has a harder edge than the standard SL, it hasn’t lost that car’s ride comfort.

AMG sports suspension and Active Body Control manage  to provide a supple ride, yet decent control, and there’s  no hint of shake in the cabin.  If there is a weak link, it’s the seven-speed auto gearbox.

It works well enough in fully automatic mode, although there’s the odd jerk if you’re  in any way hesitant with the  accelerator. And when you change gears using the car’s  steering wheel-mounted  paddles, there’s a frustrating delay on downshifts.

Gearbox aside, the SL63  is an incredibly accomplished car, mixing genuine supercar  performance with day-to-day  usability. It’s a lot like the SL500, only even faster and  with a more intoxicating  soundtrack. Job done, AMG.