An all-electric S-Class the EQS is not. I was told this by one of their representatives, who detailed that Mercedes's electric range-topper is a hatchback and, as such, the rear seat treatment is different. What the EQS is, is the first all-electric luxury saloon from Mercedes-EQ. It is also the first bespoke model to be based on its modular architecture for luxury and executive-class electric vehicles. 

Electric S-Class or not, the EQS follows in Mercedes's big-car history, by debuting 15 innovations and fusing technology, design, functionality and connectivity.

Outside from the front, the lack of an engine has had a real effect on the EQS's styling. Much more cab-forward and with a shorter overhang, there is no need for a grille. Instead, the grille space holds the iconic, three-pointed star logo. That moves sleekly into curved matrix headlights with a lamp bar stretched across the top. The lower half of the front air dam has plenty of chrome-trimmed grille, possibly making up for the lack of a central one. There is no opening bonnet - that is left for the dealer - and there is a neat filler on the left-hand side for screen wash. 

The large, mostly blocked-out quarterlights further highlight the cab-forward design. With chrome highlights, sleek metal detailing and the power pop-out door handles, the result is slick. The back, with its more coupe-like window line, hides well the fact that the EQS is a hatch, with the rear LED light design following the front. 

Inside, you could be forgiven for thinking you were in the next generation S-Class, with all the soft leather on the seats, unpolished wood on the minimalist dashboard and impressive legroom in the back. An optional 55in Hyperscreen is available, made up of three screens hidden behind a single piece of glass. Our car, however, made do with the also excellent 12.8in central touchscreen running Mercedes's latest MBUX infotainment system, which despite all its technology is easy to use. 

The driving position is comfortable and multi-adjustable, the one-piece seats are supportive and there is useful extra stowage under the raised centre console. Move to the back and like in the S-Class, legroom levels impress. Folding or not, rear seat comfort must be a match for the ICE-engined range-topper. With 610 litres of boot space, the EQS has a bigger boot than the S-Class. 

We would even go as far as to say that the EQS is more refined than the S-Class. There is a little road noise at speed, but without the amazing standard Burmeister stereo switched on, the interior driving experience is eerily quiet.

The driving experience is more conventional than the looks suggest. You start the EQS with a button and engage drive via the right-hand column stalk (as per usual Mercedes models). Behind the steering wheel is a chunky set of paddles, which work the three levels of brake recouperation. It works well; one-pedal driving suits the EQS. There are also Eco, Comfort, Sport and Individual settings. The EQS felt happiest in Comfort mode, where you can make the most of the composed ride.

Our EQS AMG Line Premium was on sharp-looking 21in AMG rims, yet the air suspension set-up made it more comfortable and compliant than the two current S-Class models we drove recently - and they were impressive themselves. The steering could do with more feel, as there is some body roll and you notice the almost 2.5t weight in corners. However, the low centre of gravity and four-wheel steering mean the EQS can slice through corners like a car half its size.