Called simply the GT, this most powerful DB7 ever is the result of almost a year's development work. Not that you'd know it from the outside, for in fine Aston Martin tradition the 435bhp, 185mph, ΂£104,500 GT is the model of discretion. Most obvious of the styling revisions are the bold, five-spoke 18in light alloy wheels, but look more closely and you'll spot a mesh grille, a pair of blistered bonnet vents and a subtly extended and upswept bootlid.

Essentially, though, the shape remains unchanged from Ian Callum's original, enduringly beautiful design. True, the lack of modern 'jewellery' such as complex-lensed lights and concealed door handles betray its years, but as few modern cars come close to matching the DB7's ability to suck the breath from your lungs, it deserves to grow old gracefully.

Don't let this mildest of exterior facelifts fool you into thinking the GT is just a gently massaged marketing exercise. Beneath its smooth, seductive skin this DB7 is shot through with carefully considered performance- enhancing revisions that temper the DB7 Vantage's stout but soft-edged demeanour into a steelier-hearted driver-focused machine. Though hardly lacking under-bonnet, careful recalibration of the 6-litre, 48-valve V12's fuelling and ignition has liberated a further 15bhp and 10lb ft of torque, hoisting peak outputs to 435bhp and 410lb ft, while a reduction in the final-drive ratio (from 4:09 to 3:77) has given the GT startling in-gear responsiveness. Other transmission changes include a new AP twin-plate clutch and a quickshift mechanism for the six-speed manual.

The chassis has been honed by Aston's own expert, Chris Porritt, along with vehicle dynamics consultant and former F1 driver John Miles. Together they have revised the damper settings to achieve better body control, fitted stiffer bushes to the front wishbones, added bracing to the rear wishbones for increased stability under braking, and improved the steering rack location for more steering feel. The brakes have also been uprated, with the fitment of grooved 355mm front and 330mm rear Brembo discs together with Pagid front pads for more progressive, consistent feel and a greater fade-resistance. The aerodynamics have been improved, too: that revised bootlid, working in unison with a new undertray and wheelarch liners, reduces high-speed lift by almost 50 per cent.

Just how effectively Callum's styling has defied the march of time is even more apparent when you get behind the wheel. The switchgear, column stalks and ventilation controls look at least a decade old, while the driving position is pretty cramped, even for a comfortably sub-six-footer like myself. The steering column adjusts for rake and reach, but not enough to compensate for the high-set driver's seat, so don't be surprised to find the ignition key fob brushing the top of your leg. The footwell is tight too, depriving you of the luxury of a rest for your left foot. It is possible to get comfortable in the GT, but it takes a day of fine-tuning to achieve it.

Not that any of this bugs you for long. There's something uniquely magical about a V12 engine that unfailingly makes your ticker beat that little bit faster. Perhaps it's the potency and complexity, or perhaps it's the shameless ostentation of having a dozen cylinders at your disposal when as few as half that number could yield the same power with some judicious turbo or supercharging. Whatever it is, the GT's 6-litre V12 has that rare talent of making you feel like a schoolboy again as you embark on the delightfully melodramatic starting procedure. Twist the ignition key, dip the clutch, then watch as the big red starter button illuminates. Pause for a moment to smile and relish the anticipation before prodding it with your left forefinger and listen as the starter motor spins busily for a second before all twelve cylinders punch into life. Utter seduction before you've even turned a wheel.

Call me old-fashioned, but it's great to have a clutch pedal in the footwell and an H-pattern gearlever atop the transmission tunnel, for I reckon there's no more involving or rewarding way to control a car. So what if the clutch pedal requires more of a shove than your calf muscle is used to mustering? Who cares if changing gears manually takes an additional few tenths of a second per shift? If you're really that disinterested in driving there's always the five-speed Touchtronic GTA. However, even Aston doesn't expect to sell many self-shifters, despite predicting the new GT will account for half of the 1000 or so DB7s built every year.

You need to be on your mettle to pull away smoothly in the GT, for the weighty clutch bites impatiently from a standstill, a trait compounded by a slightly jumpy throttle. Consequently, it's easy to invoke a shunty kangaroo start, or worse a dead stall. There's a knack, of course, but in the cut-and-thrust scenario of a busy junction or roundabout, the GT's occasional truculence can make you feel like a learner. On the move, however, it all gels perfectly, the substantial, alloy-knobbed lever snicking home with seamless precision as you short-shift through the gears, cantering along as six litres of muscle begin to limber up.

It's about now that the sheer otherworldliness of the GT's performance begins to hit you. Just exploring the foothills of this mighty engine's mountainous reserves of power and torque is a lesson in the merits of excessive cubic capacity. Far from feeling compelled to drop into second and nail it, you are instead drawn to play a far more satisfying game. Selecting a suitably tall gear, say fourth, at less than 20mph, you simply squeeze the throttle into the carpet and track the speedo needle as it surges around the dial. This walking-speed-to-warp-speed game is hypnotic and hyper in equal measure, and a form of amusement open only to those fortunate enough to drive some of the world's most potent machinery. It's also entertainment best indulged at a test track or in Germany, as even fourth gear sees the GT to 130mph. Our performance testing was curtailed by technical glitches, but the figures, especially the in-gear times, hint at the vast potential.

If there's an upside to the snug cockpit it's that it promotes a sense of intimacy with the car. Despite the obvious performance potential, the GT isn't intimidating to drive, as you're always aware of its extremities, which makes it easy to place confidently on the road. Nor does it have any nasty surprises up its immaculately tailored sleeve, for the classic front-engined, rear-drive layout ensures it maintains a level of neutrality and predictability that puts you at ease. There's plenty of feel through the fat-rimmed steering wheel and just enough body-roll to gauge how hard you're leaning on the front end.

At 1770kg, the GT is hefty (though 65kg lighter than the Vanquish) but the weight doesn't blunt its fluidity, nor its agility in repeated direction changes. While never what you'd call darty, the GT's nose can be steered enthusiastically through a series of bends without inducing more than a hint of settling understeer. What's more, when you're able to get on the power as the bend opens out, the transition into oversteer is deliciously progressive (assuming you've disabled traction control first). To say it suits a slow-in-fast-out technique is doing it a disservice, but with so much instantaneous grunt to propel you out of the turn, you've always the luxury of adopting a less frantic approach to your corner entry.

As we've said, the GT is a big, heavy car with a big, heavy V12 up front, but even on the horribly lumpen, awkwardly subsiding fenland roads that form a part of our test route, it never runs out of suspension travel. This eery, bottomless feel to the GT's damping and immaculate body control never ceases to amaze. It's more than a little reminiscent of Lotus's finest products, which is unsurprising given ex-Hethel man John Miles's input into the GT's chassis set-up. What it does prove is that a pliant ride and taut handling aren't mutually exclusive, even in an accomplished but ageing 185mph supercar like the DB7. Given Ferrari has failed to strike that balance with the newer 575M Maranello, which is horribly under-damped as standard and sharp-handling but jagged-riding with the optional 'Fiorano' pack, Porritt and Miles's achievement is all the more impressive.

Where does the DB7 GT fit into the grand scheme of things? Well, despite a tightened dynamic focus, it lacks the outright aggression of a 575M or Porsche's 911 Turbo. The Mercedes SL55 is faster, but a closer match in character, purpose and price. However, the Aston's competitive pricing, bespoke exclusivity and sheer class make the Merc look expensive for an off-the-peg item. Ultimately the GT will find buyers precisely because it's an Aston and not a Porsche, Ferrari or Maserati. That it's also the finest DB7 in the model's ten-year history makes it all the more tempting.