The C300's 3.0-liter V6 makes 228 horsepower and is quite flexible, with maximum torque for 90 percent of your driving needs available from 2700 to 5000 rpm.   The standard six-speed manual is easy to operate with light clutch and shifter efforts; there was a hint of notchy-ness in the shifter we haven't found in cars with some miles on them.   Ratios are well-spaced to take advantage of the power and deliver good highway fuel economy; we have bettered the EPA's highway value by 20 percent in some cases.  

The seven-speed automatic transmission, whether in the C300 or C350, shifts quickly and cleanly, seamlessly transparent in comfort mode, with intelligent feedback in sport mode, and manually within parameters allowed by road speed, engine speed, gear selected.  

4MATIC all-wheel drive is fully automatic: It's always on, the driver need do nothing to engage all-wheel drive.   4MATIC is a great feature for traction and directional control in inclement weather.   An all-wheel-drive C300 4MATIC with snow tires will likely embarrass most of your neighbor's SUVs, it works so well in the slippery stuff.  

The C350 packs 268 horsepower, roughly the power of the very first C-Class AMG car, the C36.   Plant your right foot and 60 mph comes up in a shade more than six seconds (one second quicker than the 300), and there isn't much to it.   We found the C350 responds to the steering wheel crisply, allows minimal body roll to keep you more aware, and changes direction quickly, all while retaining a compliant ride that moves only the tires around impacts, not the whole car.  

Luxury and Sport versions both have great road feel and steering, to the point that BMW's perceived advantage is no longer as distinct, and a rear-drive C-Class competes with anything in the segment.  

Luxury models prioritize ride comfort, so the shocks are designed to allow free suspension movement over smoother surfaces while firming up on rougher roads so the car doesn't bounce and wallow about.   Mercedes-Benz cars have always been extremely competent, inspiring driver confidence, but now they inspire the driver as well without losing any of the confidence factor.  

Sport models prioritize quicker reactions and higher cornering ability, without losing the compliance that maintains ride quality and automobile integrity.   You can upgrade sporting ability with the 18-inch wheel package that adds a half-inch to front wheel width, a half-inch to rear tire width, and employs lower profile, stickier tires.   However, the 17-inch tires with their taller sidewalls are better for rough roads, both in terms of ride quality and wheel damage.  

Brakes are sized by model to get the job done.   Initially you may feel there is a lot of pedal travel, but this allows easy modulation.  

The C63 is in another performance dimension.   At 6.2 liters its engine makes it considerably more than just a very quick compact sedan.   Mellowed somewhat to 451 horsepower, the C63 engine has 443 pound-feet of torque, with 90 percent of it available from 2000 rpm, and with the traction control turned off it can simply obliterate the C63's rear tires.  

The C63 can reach 100 mph in about the same amount of time the average car can reach 60.   The C63 can accelerate from 0-60 mph in just more than four seconds.   The Speedshift AMG automatic can be shifted manually and full-bore acceleration feels like you're driving a car with five first gears.   Alas, at 12/19 mpg, there is no way to get good fuel mileage with well over 400 horsepower.   This also results in a Gas Guzzler Tax for the C63 AMG.  

Unlike any previous AMG C-Class model, the C63 AMG has a unique front-end, including fenders, air dam, chassis, suspension, brakes and wheels.   Steering resistance adds up nicely the harder you push, limits are a long way off but three-stage electronic stability control makes them relatively easy to find when you have a racetrack for exploring, and the big engine's compression braking lets you just lift the throttle to load up the front tires for crisper turn-in, with no braking needed to upset the balance.  

The C63 is arguably the best-steering, best-handling, best driving car Mercedes builds in the sub-$125,000 range.   And it does so without active suspension or other techno-wizardry that often uses electronics to fix a chassis that wasn't ideal in the first place.   BMW and Audi loyalists will stick to their marques as each has advantages, but there is no denying that the C63 moves the C-Class AMG model beyond mere straight-line supremacy.