It's hard to believe the cabin design in the S-Class is four years old. It feels contemporary, from its broad instrument shelf, which ps two-thirds of the dashboard, to the seamless row of climate switches. The front seats are thrones of comfort — wide and flat, with enough thigh support for someone well over 6 feet tall.

The backseat is large; by the numbers, it offers more legroom than the front seats, though it doesn't quite match backseat legroom in the extended-wheelbase 7 Series and XJ. Power-adjustable rear seats are optional, as is four-zone climate control, which gives the outboard rear passengers their own zones. Our test car had both options. While logging impressions, I could have fallen asleep back there.

Mercedes' Comand interface employs a control knob for the standard navigation system. Compared with the knob-based systems from BMW and Audi, Comand is the most intuitive. The dashboard screen packs excellent graphics, and the navigation map has ample street labels. Its traffic indicators for major streets — lines of car icons in yellow or red — are easier to pick out than other systems' tiny, colored stripes. Zoom out a bit, however, and the car icons can obscure nearby streets. And Comand's voice recognition system could use some work: It didn't pick up my home street despite multiple attempts and varying pronunciation. The streets it matched weren't even close.

A standard 15-speaker Harman Kardon stereo with surround sound includes a six-CD changer, high-def and satellite radio, and full iPod compatibility. From Vivaldi to Zeppelin, it sounded superb — in the league of the Audi A8's excellent Bang & Olufsen stereo.

Trunk volume is a competitive 16.4 cubic feet. Like many top-end luxury sedans, the S-Class does not offer a folding backseat. There isn't even a pass-through for skis, a feature a number of competitors offer.