Even more surprising is the fact that the high-performance AMG is a pretty good daily driver, too … considering it has 116 more horsepower, a firmer suspension, tighter steering and loud exhaust. Those are all things an AMG buyer will want, though, and at $94,900, the performance for the money is almost a bargain.

The AMG V-8 transforms the CLS into a burly performance car that launches from the line with a grunt from the engine, a snort of exhaust and a whole lot of exhilaration. Cornering is delightful, and the steering is even more precise than the 550's.

An adaptive suspension adjusts for comfortable cruising or performance driving, delivering a more rigid ride in Sport mode.

The 2011 E63 AMG returns the same horsepower ratings, but its engine is a naturally aspirated 6.2-liter V-8. (Mercedes liberally uses 63 in the model name anyway.) The E63 AMG gets to 60 mph in an estimated 4.3 seconds, while the CLS63 AMG does it in 4.4 seconds or 4.3 with a performance package. That means once you throw on the AMG extras the E-Class and CLS-Class are much more alike than the E550 and CLS550. We'll see how similar the 2012 E63 AMG is once it's released later this year featuring the same turbocharged powerplant as the 2012 CLS.