Had we tested the all-new 2012 Mercedes-Benz M-Class in suburban Orange County, California—or even among gated exurb communities in Orange County, New York—we would likely have had affluent suburban housewives (yes, the real ones) looking us up and down. The M-Class, it seems, has become a status symbol of sorts in such places—in addition to, of course, just being a darned good family vehicle.

So why did Mercedes-Benz bring us all the way out to Big Sky Country (that's Montana to you city slickers) to test the new M-Class? Simply put, because that's where its heart is. And no matter how many grubby kids inhabit its backseat or how much time it spends negotiating speed bumps, or parked at the local gym or mall or plastic surgeon's clinic, it's at its best out on the open road, or on the trail.

It's been mostly that way from the start. The original Mercedes-Benz M-Class was a forerunner in 1998; along with the softer Lexus RX, the ML set a new standard for a generation of luxury SUVs and crossovers.

Evolved into something better

In its first generation, the M-Class was luxurious in a way that mass-market SUVs hadn't been. Yet it had a feel that was a little too trucky at times for Mercedes-Benz's cosseted customers. Then came the second-gen ML, which was a huge step ahead in refinememt and brought this wagon up to the standards of refinement and materials offered in other Mercedes products. Now the third generation is here, and to put it simply, it's even better. With top notch safety and tech features to complement its rich cabin, it not only performs better but is a safer, more responsible choice and one that might make getting there easier as well as more comfortable—a true luxury good for the 21st century.

Before we tell you about all the impressive electronic wizardry that makes getting there safer and easier, we should tell you what makes getting there more enjoyable. The clean-slate-new 2012 Mercedes-Benz M-Class is about the same weight as last year's model, yet there's more power all around—and, most of the time, a transmission that can make the most of it.

Mercedes-Benz never quite got its former V-6 to feel as smooth as the in-line six that preceded it in its cars, but the all-new, 3.5-liter V-6 in the M-Class is off to a great start. With 60-degree cylinder banks rather than 90-degree ones, plus an improved direct-injection system and an ignition system that can follow up the main ignition spark with smaller ones that bring more complete combustion. Overall, power is up to 302 horsepower, and torque is at 275 pound-feet, but what you should know is that the new engine feels perkier than the previous unit wherever it matters; and whether that's from a standing start or in quick passing on a two-laner, it sings up the rev range and works extremely well with the seven-speed automatic transmission.

Best with BlueTec

But by far, our favorite 2012 M-Class model is the ML350 BlueTec. If 'wafting' up to speed easily (without downshifts) on the highway, cruising effortlessly near triple digits, and getting gas mileage that won't place a frown on the faces of your more earth conscious friends are all priorities, you'll find this model the best fit, too. M-B has reworked this engine, too, to make 240 hp and 455 lb-ft of torque. It has a 72-degree configuration and a balance shaft for smooth operation; and notably, it runs at a lower compression ratio (15.5:1) than most diesels—helping to vary air volume quickly with the turbocharger. And as with the previous version, pilot injection from precise piezo-electric injectors helps smooth out the noise and the combustion process.

And the old assumptions about clatter and odor definitely don't hold true. Cruising inside the vehicle, we actually found the ML350 BlueTec diesel to be the quieter of the two powertrains; at all but idle, the diesel accelerated with a muted baritone that made the gasoline version seem almost a bit strident—especially in its upper rev ranges. What the BlueTec has that the gasoline engine doesn't is an almost uncanny ability to tap into its torque reserves without the drama of multi-gear downshifts. Nail the throttle down for a full-steam pass, and it's still very civil as the diesel whooshes to life with a rush of torque. M-B has added an acoustical windshield this time, a company official said, and that helps block even more of the diesel's noise.

We spent most of our time driving a BlueTec model with the Airmatic suspension and adaptive damping. The system includes just two ride modes, Comfort and Sport, and we found a very significant difference between the two; Comfort soaks up all but the hardest jolts, while with Sport you get a somewhat crisper feel at turn-in but the tradeoff is that you're at all times a little more in touch with the road surface.

The ML does feel a little more nimble with the gasoline engine, and when the road turns curvy, the seven-speed automatic doesn't work quite as well with the diesel. We noticed a moment of hesitation—enough to lose some momentum—with the BlueTec when going back into the power after slowing for tight corners; and the hesitation seemed related to shift logic more than anything, as commanding a downshift ahead of time with the steering-wheel paddle-shifters completely remedied the situation and made the powertrain feel more responsive.

With either engine, the new M-Class gets significantly better gas mileage. EPA fuel economy ratings are up to 17 mpg city, 22 highway for the gasoline ML350 and 20/25 for the ML350 BlueTec. We saw about 24 mpg with the diesel, over more than 200 miles of mostly highway driving, some of it in excess of most states' speed limits, and in a somewhat lower-speed stint in the gasoline version, we saw a still respectable 21 mpg.

New electromechanical steering doesn't quite have the dead on-center heft that some former M-B systems have had, but that's fine; it's true to the secure and confident feel of the entire vehicle, yet responds quickly when needed and has a variable-ratio rack that's handy for parking. One disappointment is the feel of the brake pedal—just a little vague and spongy, even though the brakes can haul this big ute down from autobahn speeds with total confidence.

Still surely a utility vehicle at heart

With a tow rating of 7,200 pounds, the 2012 M-Class is very capable—especially in torquey BlueTec guise—of getting the jet-skiis out to the lake. And yes, it's still fully capable of off-roading, in all but the most rocky, precarious situations. The 4Matic system's electronic, stability-system-linked 4-ETS torque distribution can send nearly all engine torque to whichever single wheel can use it. The suspension is also remarkably versatile for a combination of on-road use or off-roading—such as the dusty trails we saw out in Montana ranch country—with a so-called stroke-dependent setup that is softer when the surface demands it, firmer otherwise for more body control. Later in the model year, you'll also be able to specify an off-road package with an automatically detaching roll-bar system.

Much-improved aerodynamics—and a spoiler at the back of the roof, as well as more attention to aerodynamics in general, means that you'll rarely feel road fatigue on daylong drives; the M-Class simply feels quieter and more comfortable at triple-digit speeds—which, by the way, sneak up remarkably easy on you with the BlueTec.

For those times when you are yawning (and perhaps weaving) a little too much, Mercedes-Benz has that covered, too. Attention Assist, which takes tabs on driving style to help identify the signs of drowsy driving—triggering a coffee-cup icon and some warning beeps—is now a standard feature on all M-Class models.

Otherwise, you can count on the new sound system (or upgraded Harman/Kardon system) for some varied and superb-sounding entertainment; it includes an SD card slot, 10 GB of audio storage, CD/DVD compatibility, HD radio, weatherband, and Bluetooth audio streaming—as well as Bluetooth hands-free calling. There's also a USB port within the center console.

Top and center in the redesigned dash is a seven-inch display, flanked by air vents. Of course, it's the latest version of M-B's COMAND screen-based interface, which includes a rotary/button controller that's well placed, at the center console just ahead of the driver's right-hand armrest. We're still not wild about the interface, as the menu system begs for a simplified mode and, in our opinion, mixes higher-priority actions with ones that are rarely accessed. There are, however, a couple of programmable shortcut buttons to make it more comfortable.

And the M-Class cabin sure is comfortable, welcoming, and upscale. While the exterior is clearly a more aggressive yet graceful evolution, the interior goes in a somewhat new direction, adopting the gently sculpted lines and swooping curves of Mercedes' sedan instrument panels and complements the look with a 'power dome' center stack. And to an issue that's been criticized for years, the company has repositioned the turn-signal lever from the 8:00 position to the 10:00 position.

There's little to fault in the M-Class's driving position or comfort; though we would have liked a little more thigh support in its rather flat, wide lower cushions. Seat controls have now been moved up to the doors, as in M-B's other models. Rear seatbacks are also now adjustable for rake, and there's more than 36 cubic feet of cargo space behind the second-row seats. You'll have no problem fitting adults back there. Mercedes-Benz, curiously, is considering an available third row option for future model years.

Standout safety-tech wizardry

While its comfort, solidity, and security alone might be good reasons in and of themselves to choose the 2012 Mercedes-Benz M-Class, what makes it special among rivals is its active and passive safety. Its available Distronic Plus adaptive cruise control is one of the most sophisticated and unobtrusive systems on any vehicle—capable of coming to a full stop with traffic and restarting, and potentially reducing fatigue. The latter system includes Pre-Safe, which will now give a warning beep, followed by partial braking, then 100-percent braking in the final 0.6 second before impact, to either lessen the impact or help avoid it altogether. Lane Keeping Assist (which gently vibrates the steering wheel) and Blind Spot Assist might also save you from close calls when you're distracted by the kids.

An Advanced Park Assist system, which helps steer the vehicle back into a parallel-parking space as the driver controls the accelerator and brakes, is also available.

Among the other standouts among available features is a heated or cooled cupholder that can heat up to 141 degrees F. It did a great job keeping our coffee hot while running the A/C. And there's a new iPad docking station—positioned between the front seats and in view for rear passengers—that will be available first in this product but will soon be available for all Mercedes-Benz models.

As before, the M-Class will be built at Tuscaloosa, Alabama. And if you still need more, hold on; next year, V-8 models are on the way—as well as a base 2WD ML350.

All said, our time with the new M-Class reminded us how much luxury SUVs and crossovers have reformed with the times. The new ML350 and ML350 Bluetec are now every bit up to the standards of on-road refinement of, say, the E-Class, while still fully up to a rutted ranch trail.

Only with the desirable, well-rounded luxury good that Mercedes-Benz has created here, it's a lot more than that.