A fully automatic and filtered climate control system is now standard, using an air conditioning compressor with much larger capacity, 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 dash. 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 automatic. There are three big new dials to play with. They're quite conspicuous and entertaining, with circumference rings 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 new rear console (with two cupholders) allows passengers to set the 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. High technology at work.

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 where it can be easily read inside the tachometer, and 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.

We had a couple small problems with the function of the instrumentation and controls, however. 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). And when our ML500 arrived, the interior lights were totally turned off, which we discovered in the dark and couldn't remedy in the dark. Even with the door opened, the only light we could get was out of the glovebox. We never did solve it. It may have been a blown fuse.

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 Modular Control System consists of 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, although if you have that many favorite radio stations you need a life.

We're not sure if the Bose premium sound system is worth $1200, that's an individual thing, but we are sure that the sound quality is really great. One problem, though, is that because the navigation system takes a CD, you can't listen to CD music and be navigated at the same time (although you can listen to the radio). On long trips, you have to choose; switching CDs is cumbersome, with the slot located behind the navigation/radio screen. But at least you'll be listening to sounds you like when you're lost.

Speaking of getting lost, we attempted to navigate the navigation system without the manual, and we're not sure what we got. Well, we did get a female voice telling us to make a U turn, if possible. Three times in 300 yards, she told us that. We tried to tell her that we were, at that moment, crossing over a half-mile-wide river on a two-lane steel bridge, but she wouldn't listen. Like all current navigation systems, it takes a little time to master, and the directions are not always 100 percent.

There are no less than four power ports in the cabin, front and rear. There are good storage compartments all over. 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 low step-in height by SUV standards, but 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. Another feature that makes you feel secure is Parktronic, which beeps as you're backing up, indicating how close you are to an object. We wish they'd put this system on big pickup trucks.

The seats are wide yet supportive, 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 rear seat is one of the best in the sport-utility business. It's actually three individual buckets that can be folded separately to maximize 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 some compact sport-utilities, although less than full-size models such as the Lincoln Navigator and Cadillac Escalade.

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.