Debuting a few years ago as the successor to the Seville, the STS (Seville Touring Sedan) made it clear that Cadillac was serious about going tire to tire with Europe's iconic luxury sport sedans. The 2007 Cadillac STS has the looks, power, performance and luxury trappings to make it an enticing package.

The STS wears the company's new design language well, tastefully incorporating the trademark egg-crate grille, stacked headlights and sharply creased body panels. The STS' platform is based on that which underpins the CTS and SRX models, meaning a fair amount of athletic DNA is in this larger sedan. Plenty of handsomely stitched leather and fillets of wood trim fill the cabin, and the latest technologies, such as a head-up display and Bluetooth connectivity, are found here as well. Thanks to special attention paid to things like door seals and dash insulation, the STS is (according to the company) the quietest GM car ever made.

With a pair of powerful engines (a 255-horsepower V6 and 320-hp V8), a well-sorted suspension that blends a nice ride with athletic handling, and powerful brakes, the STS gives nothing away in terms of overall performance to its closest rivals.

The 2007 Cadillac STS occupies a niche of sorts. Sized more like a full-sizer (at 196.3 inches long, it's 6 inches longer than a Mercedes E-Class) yet priced more like a smaller premium-badged car, the STS would seem to represent a good value. Of course, that would only be true if this Caddy could comfortably compete with cars like the E-Class, BMW 5 Series, Audi A6, Infiniti M35/45 and Lexus GS series. It does suffer in a few areas, such as interior materials quality and the lack of an available manual transmission. But these aren't major issues, and with such a strong, well-rounded personality, the STS has no problem taking on challengers on the world stage.

Cadillac offers the STS with a V6 or V8 engine and rear- or all-wheel drive. All versions feature 17-inch wheels, leather seating, aluminum interior trim, eight-way power front seats, dual-zone climate control, remote vehicle start, XM satellite radio, an eight-speaker Bose sound system and OnStar. The V8 version adds a CD changer, memory seating presets, heated seats (front and rear) and steering wheel, real wood trim and rain-sensing wipers. Many of the V8's features can be added to the V6 model via a trio of packages. Other features available on both models include a DVD entertainment and navigation system, adaptive cruise control, a head-up display, and heated and ventilated front seats. An adaptive suspension system (Magnetic Ride Control) is also available, as are larger 18-inch wheels. Available only on V8s are xenon headlamps with washers and the "Intellibeam" system, which automatically controls the high beams.

STS buyers have a choice of two engines: a 3.6-liter V6 (255 hp and 252 pound-feet of torque) and a 4.6-liter V8 (320 hp and 315 lb-ft of torque). The V6 comes paired with a five-speed automatic transmission, while the V8 is matched to a six-speed automatic. Both transmissions feature regular and sport shift programs. There is also the choice of rear-wheel drive to maximize performance and economy, or all-wheel drive for better all-weather traction. The standard V6 is able to get the big sedan up to speed with surprising gusto. But step up to the V8 and the STS really shows its mettle -- we recorded a 0-60-mph time of 6.3 seconds and a quarter-mile sprint of 14.4 seconds.

Antilock disc brakes, stability control, a tire-pressure monitor and a full complement of airbags are standard on every 2007 Cadillac STS. The airbags include front-seat side and full-length side curtains. In IIHS frontal-offset crash testing, the STS scored a rating of "Good," the highest possible.

The optional Magnetic Ride suspension offers Touring and Sport modes. In Touring mode the Cadillac STS provides a cushy ride and composed handling; indeed, the car will dive into the turns with unwavering composure and never feels as if it's sprung too softly. In the Performance setting, the handling is a little sharper and the ride a bit stiffer, but the STS handles so well in Touring we question the necessity of the two settings. Overall, this large car feels three-fourths its size when driven with enthusiasm, yet it rides like a luxury car when you're spinning up the miles on the highway. Braking is strong as well, with progressive pedal action and an impressively short 120-foot stopping distance from 60 mph.

Eye-catching design, the use of premium materials and overall fine fit and finish mark the Cadillac STS' luxurious cabin. With its eucalyptus wood trim, handsomely stitched leather and waterfall-style center stack, the STS' inner sanctum looks and feels top-shelf. However, there are a few small demerits, such as a few lower-grade plastic trim pieces and an unfinished edge near the nav screen. Most of the luxury features are easy to use, with the exception of the confounding memory-setting procedure for the driver seat, mirrors, radio and climate controls. Unlike traditional systems, which place the buttons on the door or console, you must dive deep into the nav screen to set the memory in the STS. A four-color head-up display, Bluetooth connectivity and an optional 15-speaker Bose 5.1 surround-sound audio system should satisfy the most ardent technophile.