Under the bonnet, drivers have the widest and most technologically advanced choice of engines in the luxury segment, with three kinds of Hybrid powerplant to complement the usual petrol and diesel options. All-LED lighting technology and a futuristic suspension option complete a ground-breaking package. Boardroom buyers must consider it.

The key to this car is a sense of well-being; a reassurance that you're in the most thoroughly-engineered vehicle money can buy. That starts from the moment you ease yourself behind the wheel and take in the quietly classy dashboard, sink into seats that feel as if they've been tailored to fit and start wondering how you're ever going to learn how this massively complex Mercedes works.

The S-Class is an elegant design, ever an expression of luxury and the automotive grandeur of its era. It’s a heritage more evident than ever in this sixth generation model with its classic architecture and flowing silhouette, a look that may be a touch more discreet than before but is also a little more sophisticated with its long bonnet, flowing, domed roofline and gently slanting rear end.

At the front, the grille is bigger than before, the air intakes more prominent, while the styling around the advanced LED headlights and the way that the airflow is managed is just a whole lot more detailed. It’s all indicative of the optimally co-ordinated care that’s gone into all the things you can’t see, like a sleek, wind-cheating and much stiffer bodyshell, half of which is fashioned from lightweight aluminium.

Moving back, you’ll appreciate the taller and more dignified glasshouse, emphasising a profile that's a little more saloon and a little less coupe-like now that Mercedes has its CLS-Class four-door coupe model to fill that role – and indeed the separate S-Class Coupe variant.

Drop inside and drivers of the previous generation version will notice the more spacious feel, with significant amounts of extra head, elbow and shoulder room in a less cluttered cabin that's a long way removed from the button-fest that many Mercedes owners are accustomed to. Smooth curves and horizontal elements give a feeling of width, solidity and elegance without compromising on ergonomics, although I have to wonder whether BMW has better rationalised the mix of buttons and on-screen menus.

Rear seat passengers are even better provided for, as is appropriate in a car that many owners will want chauffeur-driven. They’ve 14mm more knee room and 9mm more shoulder room than they would have had in the old MK5 model and of course, in the kind of long wheelbase guise I have here, there’s plenty of room to stretch out and relax. The ‘Executive Rear’ package that gives you an electrically operated, ventilated seat with powered side and rear window blinds for extra privacy and a backrest adjustable by up to 43. 5-degrees. Plus the ‘Rear Seat Comfort’ package that gives you a seat massage function and seatback-mounted entertainment screens. They’ve to be operated by a fiddly remote control though, which seems rather out of date in these days of touch screen technology.

In sixth generation form, it remains a step ahead of its luxury segment rivals. No other rival has as difficult or as wide-ranging a brief – but then no other car brings this one’s timeless clarity and effortless superiority to such an advanced and wide-ranging portfolio of talents. It can power to supercar speeds in AMG guise, deliver nearly 100mpg in Plug-in Hybrid form and can be specified to eerily steer, power and brake itself at a cruise in whatever form you decide upon. Magic Body Control can even make bumps and potholes disappear, transforming the roadway into a magic carpet.

No other car you could choose can do all of this, which is why this S-Class will remain a benchmark for the kind of luxury saloon every prestige brand would like to build and a reference point for the current state of automotive technology. The best car in the world? You’ll feel like it is if you buy one.