There are some nice, high-grade materials in the R-Class' cabin, but it's showing its age and would have benefited from an update like the exterior received.

The most disappointing part of the cabin is the optional Comand system, which controls the navigation and audio systems, among other features. Unlike some other Mercedes models, including the S-Class and E-Class, that have the system's controller knob on the center console, the R-Class utilizes a keypad on the dash. It's a bit half-baked — and not nearly as easy to use.

Comfy front bucket seats are a plus, and the second row is downright huge; in terms of legroom and overall comfort, it's as accommodating as an S-Class. Six seats in three rows are standard, but an optional seven-seat configuration adds a narrow seat between the second-row buckets.

The third row is roomy enough. I'm 6-foot-1, and I could sit back there with the second row scooted forward some.

There's not much cargo room when all three rows of seats are up — 15.2 cubic feet, which is about what you'd get in a midsize sedan's trunk — and that lack of space might make it hard to pack for a family road trip. You get considerably more room in a three-row minivan, like the Chrysler Town & Country (33 cubic feet) or Toyota Sienna (39.1 cubic feet). Folding the Mercedes' third row yields 42.2 cubic feet of space, and there's 85 cubic feet when both the second and third rows are down.