Automotive critics tend to champion traditional wagons over crossover SUVs, but the three-row 2014 Mercedes-Benz GL-Class has us playing devil's advocate. Sure, Mercedes continues to offer the E-Class wagon with a rear-facing third-row seat, but only kids can fit back there -- and their feet will be pointing the wrong way. As for cargo capacity, no wagon's going to touch the GL's 93.8 cubic feet of space, and its air suspension provides a useful 7.8 inches of standard ground clearance, with more available at the touch of a button. Could it be that the gargantuan GL-Class just makes more sense?

Even the most curmudgeonly critic can admire the GL's vast range of talents. It's got a real third row, for one thing, with two adult-sized seats that make it a legitimate seven-passenger vehicle. In addition to all that cargo room, the GL boasts an impressively well-finished cabin and the expected long list of standard and optional luxury and convenience features. What about fuel economy, you ask? Well, the diesel-powered GL350 Bluetec is rated at a healthy 22 mpg combined (with a 26 mpg highway figure), though the available turbocharged gas V8s will tempt you with their remarkably swift acceleration. With the GL, you get stout towing capacity as well: 7,500 pounds when properly equipped.

The critic will have a point about the GL's handling; this is a big, heavy vehicle, and unless you're driving the GL63 AMG, you're going to feel that bulk every time you round a corner. Then again, nimble moves aren't really a priority for a vehicle like this. Nor are there many notable alternatives in this exclusive segment for 2014. The 2014 Infiniti QX80 offers brash styling and old-school V8 power, while the 2014 Lexus LX 570 boasts a big V8 of its own along with real off-road capabilities. But when you tally up the scores, the GL leads the way in practically every category. Some of us might still take that wagon instead, but as full-size, three-row luxury SUVs go, the 2014 Mercedes-Benz GL-Class is tough to top.

A large, seven-passenger SUV, the 2014 Mercedes-Benz GL-Class is offered in four models: GL350 Bluetec, GL450, GL550 and GL63 AMG.

The GL350 Bluetec and GL450 come with different engines (a turbocharged diesel V6 and a turbocharged gas V8, respectively), but are otherwise similarly equipped with 19-inch wheels, roof rails, a self-leveling air suspension, automatic headlights, LED running lights and taillights, rear privacy glass, a power liftgate, a sunroof, power rear quarter windows, a rearview camera, cruise control, dual-zone automatic climate control, MB-Tex premium vinyl upholstery, heated eight-way power front seats (plus four-way lumbar adjustment), a leather-wrapped tilt-and-telescoping steering wheel, wood interior trim and a power-folding third-row seat. Electronic features include the knob-based COMAND interface, a 7-inch central display, Bluetooth phone and audio connectivity, Mercedes mbrace2 communications (including smartphone app integration) and a sound system that features HD radio, an auxiliary audio jack and a USB port.

The Premium 1 package for these two models adds power-folding exterior mirrors, auto-dimming mirrors, illuminated front door sills, heated and cooled cupholders, a rear 115-volt household-style power outlet, multicolor ambient lighting, a power-adjustable steering wheel, a 10-way power driver seat, driver memory functions, voice command functionality with a learning feature, a navigation system, 10 GB of digital music storage, satellite radio and an iPod interface. The Lighting package tacks on adaptive bi-xenon headlights with adaptive high-beam control, while the Lane Tracking package adds a blind-spot monitor and lane-keeping assist. The Parking Assist package adds front and rear parking sensors, an automated parallel-parking system and a surround-view parking camera system.

The GL550 starts with all of the above, including the option packages, and ups the ante with a stronger V8, 21-inch wheels, adaptive suspension dampers, sporty exterior styling cues, keyless entry/ignition, soft-close doors, unique dashboard stitching, different wood trim, triple-zone automatic climate control, leather upholstery, ventilated "multicontour" front seats (including adjustable bolsters, massage and enhanced lumbar adjustment), a power-adjustable wood-and-leather steering wheel and a 13-speaker Harman Kardon surround-sound audio system with a six-CD changer and an SD card reader.

Many of the GL550's standard features are offered on the lesser models as options. Extra-cost items on all three non-AMG models (GL350, GL450, GL550) include a panoramic sunroof, heated second-row seats and the Driver Assistance package, with adaptive cruise control and advanced driver warning systems (see the Safety section below for more details).

The top-of-the-line GL63 AMG starts with all of the above equipment and adds an even more powerful V8 engine, a sport-tuned suspension, adaptive stabilizer bars (the "Active Curve System" in Mercedes-speak), exclusive 21-inch wheels, AMG-specific styling elements and a microfiber-trimmed sport steering wheel. A 14-speaker Bang & Olufsen surround-sound audio system is available on the GL63 AMG only.

Optional on all four GL models are a trailer hitch, various alternative interior trims, power-sliding second-row seats for third-row access, rear side window sunshades, a rear entertainment system and a Splitview display for the COMAND system that can project different images to the driver and passenger.

Note that the GL450 and 550 can be equipped with an On-/Off-Road package that includes the adaptive suspension dampers, a six-mode terrain selector and front underbody protection.

The 2014 Mercedes-Benz GL350 Bluetec is powered by a diesel-fueled 3.0-liter turbocharged V6 engine rated at 240 horsepower and 455 pound-feet of torque. Like every other GL-Class model, it features all-wheel drive and a seven-speed automatic transmission. In Edmunds performance testing, it went from zero to 60 mph in 8.4 seconds, which is slow by segment standards. EPA-estimated fuel economy stands at 22 mpg combined (19 mpg city/26 mpg highway).

The GL450 gets a gas-powered 4.7-liter turbocharged V8 that produces 362 hp and 406 lb-ft of torque. Acceleration to 60 takes just 6.2 seconds, which is impressively quick for a luxury SUV with a "base" level engine. Its fuel economy is estimated at 16 mpg combined (14 mpg city/19 mpg highway).

The GL550 gets a more powerful version of the same engine good for 429 hp and 516 lb-ft of torque. It hits 60 mph in 5.4 seconds and returns an estimated 15 mpg combined (13 mpg city/18 mpg highway).

The GL63 AMG features a 5.5-liter twin-turbo V8 good for 550 hp and 560 lb-ft of torque. Fuel economy checks in at 14 mpg combined (13 mpg city/17 mpg highway). According to Mercedes, it'll go from zero to 60 in 4.8 seconds.

Properly equipped, the GL-Class can tow a maximum of 7,500 pounds.

The 2014 Mercedes-Benz GL-Class comes standard with antilock brakes, stability control and traction control, active front head restraints, front and rear side airbags, full-length side curtain airbags, a driver knee airbag and a driver attention/drowsiness monitor. The mbrace2 communications system includes automatic collision notification, an SOS button, stolen vehicle location, geo-fencing, alarm notification and remote door lock/unlock.

The GL offers two levels of optional blind-spot and lane-departure protection. The first level comes via the Lane Tracking package (standard on GL550, optional on GL350 and GL450), which monitors blind spots and lane drifting and alerts the driver by vibrating the wheel or emitting a beep. The second level is found in the optional Driver Assistance package (standard on GL63), which adds "active" versions of these systems that can apply the brakes if the driver fails to heed the car's warnings.

In Edmunds brake testing, all non-AMG GL-Class models came to a stop from 60 mph in around 115 feet, an exceptionally short distance for such a heavy vehicle with all-season tires.

Mercedes likes to call the GL-Class a three-row S-Class, and based on its highway manners alone, we're inclined to agree. The GL tracks straight and true, shrugging off pavement imperfections and generally feeling invincible. Credit here is partly due to the standard Airmatic suspension system, which automatically lowers the vehicle at higher speeds for improved road holding. Of course, an SUV that weighs 5,500 pounds (or more) is in fact far from invincible, but that's where the GL's astoundingly powerful brakes come in: This SUV's stopping distances in our testing beat out some sport sedans.

Among the V8-powered models, acceleration is excellent even in the bottom-tier GL450, and it only gets wilder in the GL550 and GL63 AMG. If you want a crossover that can embarrass some muscle cars at the drag strip, any GL-Class V8 will do the trick. Although the diesel GL350 Bluetec isn't nearly as fast as its siblings, it feels plenty capable in everyday driving, particularly off the line.

Unfortunately, that straight-line goodness is somewhat dampened by the GL's lackluster handling. The vehicle's overly light steering and bulky size and weight are part of the problem, but so is a very intrusive stability control system that intervenes in even seemingly normal situations (say, on sharp corners at normal speeds or over broken pavement) where the GL is still in fine shape otherwise. It's not something we expect most GL drivers to be truly annoyed with, but it's a potential distraction if your driving style is on the assertive side.

Big station wagons used to be the ultimate road trip vehicles for American families, but the seven-passenger Mercedes-Benz GL-Class just might be the current luxury family vehicle champ. Unlike many three-row crossovers, the GL has a truly full-size third row, so no matter who's sitting back there, chances are they'll fit with room to spare. Moreover, the available power-entry second-row seats make third-row access incredibly easy by crossover standards (minivans still reign supreme, of course). The GL also offers seemingly endless comfort and convenience features to keep passengers comfortable, including heated seats, a dual-screen entertainment system and a panoramic sunroof. As for the people in front, they're treated to comfortable, supportive seats that only get better with the available multicontour design and massage functions.

Materials quality is excellent in the GL's cabin, with supple, tight-fitting panels everywhere you look. The many technology features start with Mercedes' excellent COMAND system, which consists of a central color screen, dashboard buttons, steering wheel controls and a multifunction knob on the center console. It can seem a little intimidating at first, but COMAND is one of the best interfaces on the market, enabling both simple and more complex tasks to be executed with ease.

Even with all three rows occupied, there are still 16 cubic feet of cargo space left behind the third row, which is about the size of a midsize sedan's trunk. With both the second- and third-row seats lowered, the GL can carry up to 93.8 cubic feet of cargo, a fairly generous amount for this segment.