Now this is an overdue vehicle. Mercedes was ahead of the SUV curve back in 1997, when it first introduced a luxury SUV—the original M Class. But it has taken the German automaker nearly nine years for an update, and in the meantime, Lexus, BMW, Acura, and even Volkswagen have raised the bar with one innovation after another: slick handling, great interiors, every electronic option imaginable, and even a Lexus hybrid.

Mercedes has finally caught up. The new M Class could stand for modern in every sense of the word, from the four power outlets that can charge everything from BlackBerrys to power tools, to rugged off-road capability that many competitors can't quite match. Most important, the ML has the soft, sedanlike driving characteristics that anybody paying upward of $40,000 for an SUV demands these days. That comes from features like an independent suspension, both front and rear, that helps dampen road vibrations and eliminate the bump-and-grind sensation that truck-based SUVs often convey. A seven-speed automatic transmission—most are four or five speeds—adds to smoothness, too, since it allows the engine to work more efficiently, makes shift points less abrupt, and helps improve gas mileage. For a tall and relatively heavy vehicle, the M Class is disciplined and upright on curves. It moves quickly and fluidly among traffic. And it is a fully qualified off-roader too, with full-tilt-boogie four-wheel drive instead of less rugged all-wheel drive. Options, like specially modified off-road antilock brakes and an air suspension system that raises ground clearance, will convince die-hard trail buffs.

With all the mechanics in place, it's easy to enjoy the ample amenities of the smartly engineered cabin. The machined, masculine exterior design of the M Class extends to the interior. On the model I tested, brushed nickel inserts on the doors matched up cleanly with similar accents elsewhere. Air vents flare up out of the dash like muscles meant to impress, yet they flow seamlessly into the surrounding components. The styling is bold, but there's no faux artistry, thank goodness, since lesser cars are full of it. You can also pack this vehicle with as many doodads as you want, though the profusion of controls for seat warmers and suspension settings and electronic menu options borders on overkill. Other features are mercifully simple. The rear seat folds flat with two easy maneuvers, leaving a cargo area that's bigger than you'd guess just looking at the SUV from the outside. And visibility is excellent all around, unlike more swept, avant-garde competitors like the Infiniti FX. Credit the countertrendy tall design. And hope this serious, superb SUV compels other good ones to get even better.