Anyone accustomed to S-class luxury but needing more space or ground clearance will feel right at home in the three-row GLS-class SUV. It offers a pair of engines—a 375-hp turbocharged inline-six in the GLS450 and a 510-hp twin-turbo V-8 in the GLS580—that provide smooth-as-silk propulsion and swift acceleration. A standard air suspension keeps it on an even keel, providing great body control and contributing to crisp handling, attributes that aren't a given for a vehicle of this size. Speaking of footprint, there's plenty of room inside the SUV's modern cabin, with seating for either six or seven and sufficient cargo space. The speed-obsessed may want to check out the 603-hp GLS63 while oligarchs in training will gravitate toward the Maybach GLS600. Competition includes the equally athletic BMW X7, as well as the ubiquitous Land Rover Range Rover and the all-American Lincoln Navigator.