Beauty has its price, and the 2013 Mercedes-Benz CLS-Class is a prime example. There's no doubt the CLS has a presence about it. Its stretched, sleek and athletic stance basically invented the "four-door coupe" body style in 2006. But under the gorgeous sheet metal, the CLS shares its underpinnings with the more affordable Mercedes-Benz E-Class, and it's clear that such style comes with its own compromises.

Consider for a moment that the 2013 Mercedes-Benz CLS-Class costs considerably more than a similarly equipped E-Class sedan. To compound matters, the backseat of the CLS suffer from a lack of headroom -- a consequence of the sweeping roof line that defines the car's shape.

Now, don't get us wrong -- if money were no object, the CLS 550 and its bonkers 550-horsepower CLS63 AMG stablemate would definitely be on our "must-have" list. In typical Mercedes-Benz fashion, the CLS-Class delivers impeccable ride quality, confident road-hugging handling, a long list of standard and optional high-tech features and an interior that is, quite simply, beyond reproach.

Granted, the same can be said of other luxury sedans in this segment, and some of them are also variations on the four-door coupe theme. The latest entrant is the BMW 6 Series Gran Coupe, which gains favor with a bit more rear headroom. Even more headroom can be had in the Porsche Panamera, though most will agree that it looks pretty homely by comparison. One could also look at the more shapely Audi A7 and S7, which are less expensive and offer standard all-wheel drive.

The good news is that there's no bad choice in the bunch, even when you factor in the cost of beauty in the 2013 Mercedes-Benz CLS-Class.

The 2013 Mercedes-Benz CLS-Class is a four-passenger, four-door sedan available in CLS550, CLS550 4Matic and CLS63 AMG trim levels.

The CLS550 and CLS550 4Matic come standard with 18-inch wheels, an adaptive air suspension, bi-xenon headlights, LED running lights, auto-dimming rearview and driver-side mirrors, a sunroof, dual-zone automatic climate control, 10-way power front seats with memory functions and four-way lumbar adjustment, a power tilt-and-telescoping steering wheel and leather upholstery. Electronics features include a 7-inch video display, the COMAND interface, a navigation system, voice controls, Bluetooth phone and audio connectivity, Mercedes' mbrace2 telematics system and a 14-speaker Harman Kardon surround-sound audio system with a six-CD changer, HD radio and satellite radio.

The CLS63 AMG adds a more powerful twin-turbo V8, a different transmission, 19-inch wheels, a sport-tuned adaptive suspension, a sport steering wheel with shift paddles, upgraded leather upholstery, a power rear sunshade, a split-folding rear seat (optional for the CLS550) and an iPod/USB audio interface. The AMG Performance package adds additional power, a higher top speed, a more aggressively tuned suspension, a carbon-fiber engine cover and rear spoiler, and a sport steering wheel trimmed in faux suede. Forged alloy wheels, a limited-slip differential and carbon-ceramic brakes are stand-alone options for the AMG.

Available on either model, the Premium 1 package adds adaptive LED headlights, automatic high beams, a rearview camera, a power trunk closer, keyless ignition/entry, and heated and ventilated front seats. On the CLS550, this package includes a power rear sunshade and an iPod/USB audio interface. The CLS63 version includes front seats with active bolsters and massage.

The Lane Tracking package adds a blind-spot warning system and a lane-departure warning system. The Driver Assistance package gets adaptive cruise control and enhanced, active versions of the Lane Tracking items. The Parktronic package includes front and rear parking sensors and an automatic parking system. Stand-alone options include an infrared night-view display, heated rear seats and a premium Bang & Olufsen surround-sound system (late availability). The CLS550 can be equipped with a heated steering wheel and massaging front seats with active bolsters.

The 2013 Mercedes-Benz CLS550 is powered by a twin-turbo 4.7-liter V8 that sends 402 hp and 443 pound-feet of torque to the rear wheels through a seven-speed automatic transmission. In Edmunds performance testing, the CLS550 went from zero to 60 mph in 4.6 seconds -- truly impressive performance for a V8-powered sedan of this size. EPA-estimated fuel economy is 17 mpg city/25 mpg highway and 20 mpg in combined driving for the CLS550, while 4Matic drops these estimates by 1 mpg each for city and combined figures.

The CLS63 AMG gets a twin-turbo 5.5-liter V8 that sends 518 hp and 516 lb-ft of torque to the rear wheels through a specialized seven-speed automatic transmission. If that's not good enough, the AMG Performance Pack pumps output to 550 hp and 590 lb-ft of torque. In Edmunds testing with the Performance Pack, a CLS63 hit 60 mph in an incredible 3.9 seconds. Estimated fuel economy with the regular CLS63 engine tune is 16/25/19.

Every 2013 Mercedes-Benz CLS-Class features standard four-wheel antilock disc brakes, traction and stability control, front knee airbags, front side airbags (both torso and pelvic), full-length curtain airbags and the updated Mercedes-Benz mbrace telematics system (smartphone integration and Web-based apps that include remote controls, driver monitoring and emergency services). Also standard is Attention Assist (a driver drowsiness and alerting monitor) and PreSafe (it anticipates an imminent crash and automatically takes measures to better secure occupants).

Options include rear side airbags, infrared night-view sensors and rearview parking sensors. The Driver Assistance package adds blind-spot and lane-departure systems; the active version of this package takes action should you fail to heed those warnings.

In Edmunds brake testing, a CLS550 with summer tires came to a stop from 60 mph in 108 feet, which is excellent but just a tad better than average for the class. The CLS63 actually took a bit longer at 113 feet, but that's still excellent.

Simply put, the 2013 Mercedes-Benz CLS550 drives beautifully. The adaptive air suspension and variable dampers provide secure handling and an impressive ride quality. The electrically assisted steering offers good feedback, loads up naturally and quickens the more you turn, making the CLS feel smaller than it actually is. Also helping that effort is a "base" engine that utterly flattens you into your seat with a simple brush of the pedal. It's hard to imagine needing any more power.

But then you drop yourself into the CLS63, brushits pedal and feel yourself melt at the glorious burbling roar of the bigger twin-turbo V8 at work. This is a truly majestic power plant, and it's complemented beautifully by a transmission that swaps gears with surgical precision. Though a manual mode with paddle shifters is included, Sport+ mode is so adept at downshifting one or two gears during braking (accompanied by the glorious bark of an engine blip) that we found ourselves never using the paddles.

Handling is also exceptional. As with the 550, the AMG's steering feels light, but there is an abundance of feel fed to your hands that rewards a delicate touch. The three-mode suspension system eliminates body roll and brings the big CLS around corners without breaking a sweat. It's quite firm even in its Comfort setting, however, so those looking for a sumptuous ride should stick with the comfier yet still composed CLS550.

As with the exterior, the CLS cabin takes the current Mercedes-Benz design aesthetic and makes it more organic and curvaceous. Materials are beyond reproach. The control layout is similar to the E-Class, though it swaps in an analog clock and the older knob-style climate controls in lieu of the newer toggle buttons. Stepping up to the CLS63 adds a chunky AMG wheel and fills the center console with AMG vehicle controls and the MCT transmission selector (complete with an embossed AMG crest) in lieu of the 550's electronic shift lever on the steering column.

With its low, racy roof line and two-passenger backseat, the 2013 Mercedes CLS isn't what we'd call the ideal people carrier. If you frequently ferry people around or have particularly tall friends, opting for an E-Class is probably a wiser idea. Trunk space is pretty generous, however, with 15.7 cubic feet available.