It's pretty hard to argue with the Bentley Continental Supersports formula, or the result. Take a standard Continental GT, lose weight (including the rear seats), add power and modify the chassis to create a vastly sharper and swifter drive. The sort of Bentley you may want to take around a track, in other words. Or, more likely, be content that you could do it in theory.

Now the same trick has been done to the convertible. No, it hasn't lost its rear seats – that would be more than a little silly in such a vast open-top. But it has shed 200lbs, even if it's still the wrong side of two tons. Nevertheless, there's lots of shove to shift that bulk. In the Supersports, the 6.0-liter W12 – capable of running on E85 biofuel – is good for 621hp and an equally impressive 590 lb-ft of torque, which catapults it to 60mph in 3.9sec and all the way to 202mph.

Headline changes to the chassis center on revisions to the four-wheel drive system so that 60 percent of the power is now sent to the rear wheels in normal driving conditions, a retuning of the electronic dampers, a wider track and an uprated rear anti-roll bar, which promises better body control, as well as the opportunity to improve agility and steering finesse. Carbon-ceramic brakes are also standard.

Bentley's engineering boss, Ulrich Eichhorn, told us he didn't believe dual-clutch gearboxes were the only answer for cars like the Continental in the future because of how conventional torque converter gearboxes are developing.

A case in point is the uprated 6-speed 'box in the Convertible. It halves shift times to 93 milliseconds, inproves acceleration and delivers double downshifts (fifth to third, for instance).

Revised engine and gearbox controllers now reduce torque during downshifts; on upshifts, fuel and ignition are cut to boost speed and smoothness. There's also no negative impact on fuel consumption. So, will the next Conti have a regular autobox? We wouldn't bet against it.

As with the coupe, you also get plenty of cosmetic enhancements – including flared rear wings, more aggressive-looking front bodywork and plenty of cabin detailing – to inform you that you're riding in the quickest open-top Bentley yet.

There are the same special, thinner yet extremely comfortable seats as in the Supersports coupe and a dashboard and center console trimmed in carbon fiber rather than the traditional wood panels.

The big question, though, is whether the open-top body style is at odds with the Supersports philosophy. Are all the things liked about the hard-top diluted with the roof removed? It takes only a few hundred yards behind the wheel to discover that it's not quite as aggressive as the coupe, not quite so raw. But Bentley's engineers saw that as being more in keeping with an open-top car. It's still a remarkably swift and surefooted car, and one that hides its mass well, too. Its body control and steering precision are superb, especially when you consider what it is you are throwing around corners. You'd have to have a screw loose to approach its limits of traction on a public road.

The duality of the Supersports Convertible is part of its appeal to me. You feel the odd wobble but, for the most part, it has a supple ride and, roof up or down, it does a good job of masking the elements. Yet a NASCAR exhaust note is only a throttle prod away. And the surefootedness means you coverground almost indecently quickly.

Downsides are few. Of course, there's the $280,000 price and running costs of a car like this and, even if you've got the wherewithal, you may still find the rear seats a little limiting. Most adults are going to feel cramped and claustrophobic after a few miles, especially with the top up. Some of the cabin controls look and feel a bit dated now, too, especially the infotainment system.

With the new Continental set to appear on the scene next year, this looks like being the last hurrah for the biggest-selling Bentley in history. The Supersports Convertible isn't our favorite Conti, but such is its pace and agility, it's hard to argue against it if you want supercar poke and the sun on your head.

Chas Hallett/Autocar