The M-Class is more than powerful enough in any of its variations. And it offers the safety equipment, luxury accoutrements, style and smooth finish expected of a Mercedes-Benz.
The M-Class has given up any pretense to being a large-family vehicle. The optional side-facing rear seats from the old model are gone (they weren't very good anyway), so the M-Class is strictly a five-seater. You'll want to look at the GL-Class for seven-seat accommodations in a Mercedes SUV.
On the practical side, the M-Class body is much more aerodynamic.
The steering wheel has a nice, thick rim that's reassuring when driving off road. We're fond of the optional steering wheel that's finished with the top half in wood and the bottom half in leather, but some drivers don't like wood or mixed materials on their wheels.
The Mercedes-Benz M-Class offers a nice balance. It's not as stiff and unforgiving as some SUVs, nor as mushy on and off road as others. It has reasonable off-road capability and good towing capacity, but it's never a chore to drive during the more mundane daily tasks most drivers will undertake. Its choice of four engines is a plus, allowing owners to tailor priorities from high mileage to high performance.