The RMS Queen Mary 2 is a 345m-long ocean liner. Resplendent with heavy wood finishes, glimmering chandeliers and opulent accommodation, it is a luxury traditionalist's dream.

If you have been on a cruise on the Queen Mary (or a similarly expansive liner) and long to take the experience on land, Infiniti will sell you the next best thing.

The luxury arm of Nissan has rolled out the QX80, a 2.8-tonne premium SUV. Standing at 1.95m tall and 2.03m wide, the car is built on a conventional ladder-frame chassis.

It was launched in 2011, selling predominantly in the United States, where carparks are sprawling, distances are epic, fuel is cheap and road tax is not pegged to engine capacity.

There, Infiniti's QX80 does titanic battle with the likes of the Cadillac Escalade, Lexus LX and GMC Yukon, all unfamiliar names in Singapore. The QX's presence here therefore requires a little explaining.

Infiniti currently does not have a large sedan to take on the Mercedes-Benz S-class or BMW 7-series. The QX80 thus plays the role of flagship. Closest to it in concept are the likes of the Range Rover and Volvo XC90 - the former is considerably costlier and both are noticeably smaller and endowed with more road-friendly monocoque chassis.

Infiniti also hopes to draw customers from price-comparable luxury saloons, but for now it exists in a class of one.

I clamber up to explore the cavernous interior and find everything to be pillowy soft to the touch and decadent in finish. There is also that wonderful towering view.

In an era of digital cockpits, the QX's interior seems slightly dated. Its touchscreen infotainment system carries third-party navigation software and pixelated monochrome adorns secondary displays.

Space is, of course, abundant and even the rear-most row is no squeeze for adults. But while riders in the middle row get airline-style individual screens and "captain chairs", they do not slide. And the rear seatbacks fold only via a painfully slow electrical mechanism.

The experience on the road is empowering. There are few vehicles that can dwarf an Audi Q7, let alone a poor Mini Cooper that hovered timidly behind, not daring to overtake.

Everywhere I go is a game of "Will It Fit?". Yet, despite having a steering that offers virtually zero tactile feedback, the QX is relatively easy to drive. Everything can be directed by line-of-sight and its 5.6-litre V8 provides effortless and accurate propulsion. Multi-storey carparks, however, are best avoided.

Concentrating hard, I can just detect the lack of a monocoque construction over harsher terrain. Its prodigious wheelbase and suspension travel often translate to uncompromising comfort and serenity. Traffic jams also lose their oppressiveness when you can see right over them.

The QX80 is not the last word in modernity, sophistication or versatility, but it is outfitted sumptuously. Still, its unbeatable size is its best feature.

To dominate one's unique selling point so emphatically is in today's crowded market a rare achievement that is charming in itself. And at less than $400,000, you might even say it is good value.