The GS is quite easily my favourite Lexus. It is sizeable, spacious and yet stunningly sporty.

The model is available with a variety of engines, but I am still partial to the "old school" GS350, which is powered by a 3.5-litre normally aspirated V6.

This high-compression dual-cycle power plant is now paired with a silky eight-speed automatic transmission. Together, they dish out ultra-smooth progress and relentless acceleration.

Even though most tasks are accomplished within 2,500rpm, the powertrain invites you to exploit its entire rev range.

When you do, you are rewarded richly with a mix of driving sensations, which are nothing short of amazing.

How does the car move from being a prim and proper executive saloon to a spirited GT in the blink of an eye?

The transformation is most pronounced when you twist the drive mode selector to Sport+. The instrumentation panel lights up with a crimson backlighting and the car raises its aggression quotient by a couple of notches.

The transmission stays in gear longer and throttle response becomes keener. You get a devilish performance, with the V6 extending readily to 5,000rpm and its peak torque of 380Nm gushing to the rear wheels - propelling the regal sedan forward with steely resolution.

It is true that many other cars offer a similar blend of emotions, thanks to an increasing availability of drive mode selection.

But the GS350's recipe is special in one aspect: It feels as comfortable, civilised and in control when it is hurtling through traffic like a sports car as it does when it is cruising lazily in Eco mode.

The throaty roar from its V6, rising in resonance as the revs pile up, is perceptible but never in your face. Its chassis remains calm and cushy, a testament to its engineering finesse.

You get to access a wide performance envelope and, at practically no expense to civility.

On this score, the GS350 can be seen as a cross between the Mercedes-Benz E-class and BMW 5-series. It is able to pamper and excite in equal measure.

For those who grow sick of the clinical efficiency of turbocharged engines, the GS350 is just the prescription. (If you want a stronger dosage, go for the 5-litre V8 GS F.)

The GS may not be as big nor as roomy as the E-class or 5-series, but it will still accommodate five with ease. In fact, its unusual dynamism may well be because it is not as big as the two Germans.

It is at the same time just as luxurious as the twin stalwarts and matches them in terms of relevant features. Lexus has steered clear of overly techie gadgets and the GS shows it.

It could, however, improve upon its placement of the parking brake and auto-hold switches. And its mouse-like toggle for the infotainment system is not the friendliest to use. The system itself is logical and intuitive, but the mechanism is just too twitchy.

Or it could be that I am just too old school.