There's a traditional Mercedes look to the white-on-black gauges, which turn ivory-on-black when lit at night. The digital clock is intelligently located inside the tachometer, where it can be easily read; an ambient thermometer is located inside the speedometer, although we believe a compass located there would be more useful. The compass is on the overhead console, one of six functions on the trip computer, along with date, present and average fuel consumption, miles to empty, and a stop watch. The cupholders that fold out of the dash on each end are the best.

Surprisingly, given Mercedes' focus on safety, there is no warning light when a door is ajar (also true of some of the company's sedans). The cruise control stalk is often criticized on Mercedes vehicles for being located above the turn signal stalk, set with an upward push. So during a right turn, your left hand flips the turn signal up, you turn the steering wheel, and if your fingers stayed extended a moment too long, you bump the cruise control stalk and set it, often without realizing it. It happened to us once, and we never knew it until we backed off for a stop sign, and the throttle stayed on.

The fully automatic and filtered climate control system uses a large-capacity air conditioning compressor under the hood and six temperature sensors in the cabin to provide efficient and accurate air temperature and flow. Theoretically, that is. We suspect there's some German over-engineering here. For example, in automatic mode, the blower speed is determined by, among other things, a photo diode that registers sunlight on the dashboard. The default temperature setting is 72 degrees. To change it, refer to your 320-page hardcover owner's manual.

But you don't have to use the automatic mode. There are three big well-designed dials to adjust manually. Rings around the circumference of the dials are used to adjust fan speed, temperature and air direction, and a little red LED light indicator that moves around the outside. However, they lack separate settings for each side of the forward cabin. The rear console (with two cupholders) allows back-seat passengers to set their own air speed and direction, but not temperature. It too has an automatic setting, meaning sunlight on the dash affects blower speed in the back seat. That's high technology at work.

The Modular Control System includes the sound and navigation systems, both displayed on a console screen. The on-off/volume button is so small it will be very difficult to grip with gloves in winter. There's another small button for tuning both radio and navigation, which works like a teensy joystick. You can preset 10 radio channels from a keyboard. There's a learning curve to mastering the system. We've never figured out how to run the navigation system without the radio stepping in uninvited, for example. The compass and trip computer display are above the mirror and hard to read.

There are no less than four power ports in the cabin, front and rear. There are good storage compartments all over, though we couldn't find a good place for toll change. We like the grab handles over each of the four doors, although climbing out isn't very difficult, as the door sills sit only 18 inches above the ground. That's a low step-in height by SUV standards.

Parktronic ($1015) is an excellent feature. The system beeps as you're backing up, indicating how close you are to an object.

The seats are supportive and comfortable, with thick, sturdy leather upholstery and enough bolstering for most SUV driving, although not enough for the cornering that the ML500 invites and ML55 AMG begs. The seats are wide, but much smaller than the mammoth seats in a Cadillac Escalade. The driver still sits tall above the pavement. The high seats, expansive glass, effective mirrors and fall-away hood combine for great visibility in all directions and a secure feeling at the wheel, though the windshield is narrow, like a turret. The rear center headrest is a great idea when five passengers are aboard, but it impedes rearward vision.

The rear seat is one of the best in the sport-utility business. It's actually three individual buckets that can be folded separately to optimize passenger or cargo space. The seat bottoms are wide and supportive, and the seats slide about five inches fore and aft, increasing either legroom or cargo space.

The M-Class's cargo capacity of 81.2 cubic feet is more than in some other mid-size sport-utilities, although less than full-size models such as the Lincoln Navigator and Cadillac Escalade. The cargo floor is not perfectly flat behind the rear seats, however.

Completely filling the large pocket in the passenger door is a leather packet with all the ML500 printed materials, including that 320-page hardcover operator's manual. Mercedes is not alone in the automotive world in its presumption that anyone who spends this kind of money on a vehicle will learn how to operate it, but mastering the controls will take a lot of learning. Another presumption might be that anyone who spends $50,000 on a vehicle will expect to have its operation made easy for them with simple or at least intuitive controls. But apparently getting sophistication without complication is a conundrum.