The revamped M-Class is a refined vehicle with an impressively quiet cabin, meticulous fit and finish, as well as excellent seats. Combined, these elements provide a luxurious atmosphere. Handling is responsive, but let down by vague steering and an unimpressive showing at its cornering limits. Ride is supple, if a bit firm. The standard V6 eagerly serves up smooth acceleration and yields 18 mpg, not bad for a vehicle of its size and weight. Some controls improved with the redesign, but others remain complicated. Towing capacity is generous. Engine choices include a turbocharged V6 and a 518-hp AMG V8.