All good things eventually come to an end, and for Mercedes-Benz, it was the G-Class. Properly known as the Geländewagen, it was boxy and tough-as-nails, but getting long in the tooth, and so the company decided to replace it with a softer, more luxurious version tuned to today's premium SUV buyer.

But the unexpected happened: G-Class loyalists rose up in arms, refusing to let their beloved model perish. And so Mercedes now has two vehicles starting with that letter, the G-Class - which it now has no plans to discontinue, but will only sell in limited quantities in Canada on a special-order basis - and the all-new GL-Class, available for 2007 as the GL450.

If the GL-Class looks familiar, that's because this seven-seater rides on the M-Class platform, a model which underwent a complete transformation for 2006. If you've driven the ML, you'll know where to find all the switches and dials in the GL, and the view down the bonnet will be the same. The similarities end under the hood, where the GL450 carries a 4.6-litre V8, mated to a seven-speed automatic transmission and with the company's 4MATIC all-wheel drive that splits torque 40/60 front to rear. Like the M- and R-Class, it's built in Mercedes' plant in Tuscaloosa, Alabama.

2007 Mercedes-Benz GL450. Click image to enlarge

The GL450 starts at $76,500, but that number can be sent north fairly quickly; options include active bi-Xenon headlamps with washers and cornering lights, three-zone automatic climate control with rear air conditioning, and an off-road package with Adaptive Damping and undercarriage protection. My tester included a leather upholstery and interior light package. Without it, you get "manmade" leather - and a Premium Package of navigation system, electrically-adjustable steering column, passenger and driver's side memory, power folding side mirrors, power liftgate and a second-row audio system.

Even without options, though, this is a well-equipped package, and includes a six-CD/MP3 player, four-wheel self-levelling air suspension, auto-dimming mirrors, automatic climate control, cargo cover, display screen, heated seats, Parktronic parking system, rain-sensing wipers and sunroof.

2007 Mercedes-Benz GL450. Click image to enlarge

Passengers are divided into three rows of seats, and unlike far too many third rows, this one is actually tolerable for adults, a trait it shares with the R-Class. The third row is accessed by folding the second row, and with the memory option, the front seat moves slightly forward electrically to make room for it when it flips down. The third row folds electrically, with convenient buttons both at the liftgate and B-pillar. With all seats up, the cargo area is 47 cm long; fold the third seats and you get 125 cm. The second row folds flat when the cushion is flipped and the backrest is dropped, and with both rows down, there's a flat cargo floor that's 195 cm long, with tie-downs.

Mercedes is all about creamy-smooth power, of course, and the GL450 delivers. The 4.6-litre makes 335 hp and 339 lb-ft of torque, and it pulls zero to 100 km/h in 7.6 seconds - all the more respectable when you realize it's hauling 2430 kg (5357 lbs). You never forget just how big this vehicle really is, and it has the disconnection from the asphalt inherent to most big, tall SUVs. The ride is ridiculously comfortable, but there's a price to pay: the GL450 leans heavily around corners, and can feel wallowy on twisting roads.

2007 Mercedes-Benz GL450. Click image to enlarge

That said, I've heard opinions from other journalists, some of whom agree with me, and others who found it nimble. I suspect that those who found sharper handling may have had the adjustable ride damping system, which tightens everything up.

I took the GL on a 400-km day trip; this vehicle is really meant for all-day cruising on the highway, where it exhibits good on-centre feel and simply lets you relax, with a minimum of corrections to keep it on the straight and narrow. The seven-speed shifts almost imperceptibly, and can be held in manual mode to run the gears out a little longer if you prefer. Keeping mostly to the highway, I was very surprised to find that I averaged 12.7L/100 km - much better mileage than I had been expecting given its size, although I did have to feed it premium fuel.

Although my tester didn't have the optional damping control system, I could still raise the air suspension at the touch of a button; most buyers won't ever do any serious off-roading, but those with cottages may find it handy for high-crowned paths. Other useful features include a downhill speed regulator, and a hill start assist system that holds the brakes for about a second, to keep from rolling backwards when moving from throttle to brake.

2007 Mercedes-Benz GL450. Click image to enlarge

Inside, the GL is finished in burled wood and double-stitched rows on all seams, including the instrument panel cover. There is full backlighting on all controls, including the overhead buttons for the sunroof, and theatre lighting behind the inside door handles makes them easy to find at night. Even the cupholders are softly illuminated, although given the smoothness of the interior, I'm surprised they don't have a cover.

The COMAND (Cockpit Management And Navigation Display) screen displays the optional navigation system; what I really like about it is that when you start the vehicle, it flashes the standard "It's-your-fault-if-you-look-at-me-instead-of-watching-the-road" warning, but then, after a few seconds, it goes to work, without requiring that you hit an "accept" button each time.

2007 Mercedes-Benz GL450. Click image to enlarge

The six-CD changer slots into the glovebox, but it's tucked up out of the way so there's still some storage space.

The gearshift is column-mounted, which frees up console space, and you simply tap it up for Reverse, down for Drive, or push the button at the end for Park. There's a bit of a learning curve in that the cruise control stalk is where most manufacturers put the turn signal switch; that control is lower, and if your hands are small and you drive at the proper six-and-three position, it can be tough to reach without taking your hand off the wheel.

2007 Mercedes-Benz GL450. Click image to enlarge

The expected niceties abound: double sun visors, centre vents that close completely, and electric up/down head restraints that can also be manually pulled fore and aft. The parking sensors use a series of yellow and red lights to indicate how close you're coming to objects; the front ones are visible on the dash, but the rear ones are over the rear window, which tempts one into the nasty habit of backing up using the rearview mirror alone. I found the audio sensors kicked in when I was about a foot away; a little earlier warning would have been appreciated.

More Test Drives....