Last year, the big news was simply that Cadillac had finally introduced a modern full-size luxury sedan. This year, though, it's all about what's under the 2014 Cadillac XTS's hood. Although we generally praised the XTS in its first year of production, we were underwhelmed by the standard 304-hp V6 engine, panning its relatively modest output given the size of the car. But the 2014 XTS has 410 reasons why power won't be an issue going forward.

That's because the new CTS sport sedan's optional turbocharged 3.6-liter V6 is available on the XTS, too. Rated at a whopping 410 hp and paired exclusively with all-wheel drive, the turbo V6 gives this dignified cruiser the authoritative acceleration it deserves. Sure, you can stick with the base V6 and still enjoy a great all-around luxury experience. But if you're with us in believing that a proper Caddy should haul the mail, the new XTS turbo, or Vsport, as Cadillac calls it, is just what the doctor ordered.

Otherwise, the 2014 Cadillac XTS is familiar from last year, and that's good news as well. This is a traditional luxury ride with a gleaming modern edge, offering age-old Cadillac virtues like comfort and space, but adding daring style outside and a festival of technology inside. Indeed, the XTS's spaceship-like cockpit and touch-sensitive control panel could be a turnoff for those who yearn for the days of simple knobs and buttons. But if you're looking for a new twist on this classic formula, few cars can compare.

Actually, few cars even compete in this segment anymore. One alternative that comes to mind is the Chrysler 300C, a fancy version of a lower-priced model; another is the Hyundai Genesis, an aging but competent rival. Then there's the Lincoln MKS, a technically similar luxury sedan that has always left us cold. On the higher end, you could look at models like the Audi A6 and Mercedes-Benz E-Class, but they're really midsize cars and don't come close to matching the Cadillac's interior room. See what we mean? There's not much else in this price range if you want a true full-size sedan. And with the new turbo V6 in the mix, the XTS's case is only getting stronger.

The 2014 Cadillac XTS is a five-passenger luxury sedan. There are four trim levels: base, Luxury Collection, Premium Collection and Platinum Collection. Note that the Premium and Platinum Vsport versions come with the optional twin-turbo V6.

Standard equipment for the base XTS includes 19-inch wheels, adaptive suspension dampers, xenon headlamps, heated mirrors, rear parking sensors, keyless ignition/entry, dual-zone automatic climate control, eight-way power front seats (with power lumbar control), a power tilt-and-telescoping steering wheel and leather/faux-suede upholstery. Standard technology features include Bluetooth phone and audio connectivity, an 8-inch center touchscreen with Cadillac's CUE interface, OnStar, voice controls and an eight-speaker Bose sound system with a CD player, satellite radio, HD radio, iPod/USB connectivity and an auxiliary input.

The XTS Luxury Collection adds LED lighting accents, visible dual-exhaust outlets in the rear fascia, illuminated door handles, rain-sensing wipers, adjustable thigh support for front passengers, extended wood interior trim, a heated steering wheel, driver and front-passenger memory functions, heated and ventilated front seats, heated rear seats, interior ambient lighting, front and rear parking sensors, a rearview camera, an automated parallel-parking system and rain-sensing wipers.

The Premium Collection builds on those offerings with adaptive headlamps; automatic high beams; a head-up display; an upgraded driver-configurable gauge cluster display; tri-zone automatic climate control; a 110-volt power outlet; a navigation system; voice controls; a 14-speaker Bose surround-sound audio system; rear seat audio controls; and a suite of safety features that include blind-spot detection, lane departure warning, rear cross-traffic alerts and front collision alerts. The Premium Vsport adds 20-inch wheels and a sportier-looking grille.

Finally, the Platinum Collection boasts 20-inch wheels with chrome accents, unique exterior styling, adaptive cruise control with low-speed automatic braking, a panoramic sunroof, a power rear sunshade, a faux suede headliner and additional cabin leather trim with upgraded upholstery for the seats. The Platinum Vsport shares the Premium Vsport's grille, but gets the same chrome-accented wheels as the regular Platinum.

Some of the extra standard features from the higher trim levels can be added to the lower trim levels via various packages. Optional for the XTS Premium and Platinum is a rear-seat Blu-ray/DVD entertainment system with dual fold-out displays.

The 2014 Cadillac XTS starts with front-wheel drive and a naturally aspirated 3.6-liter V6 engine that produces 304 hp and 264 pound-feet of torque. A six-speed automatic transmission is standard. All-wheel drive is available and can be identified by the moniker "XTS4." In Edmunds testing, an XTS4 Platinum went from zero to 60 in 7.3 seconds -- a second or so behind similarly priced and powered luxury sedans. Fuel economy stands at an EPA-estimated 21 mpg combined (18 mpg city/28 mpg highway) with front-wheel drive, while all-wheel-drive models are rated at 20 mpg combined (17 mpg city/26 mpg highway).

If you want more pep, the Premium and Platinum Vsport trims come with a turbocharged version of the 3.6-liter V6 that produces 410 hp and 369 lb-ft of torque. All-wheel drive is standard with the turbo V6, as is a six-speed automatic. The EPA rates the XTS Vsport at 19 mpg combined (16 mpg city/24 mpg highway).

The 2014 Cadillac XTS comes standard with antilock disc brakes, stability control and traction control, front and rear seat side airbags, side curtain airbags and front knee airbags. Also standard is OnStar, which includes automatic crash notification, on-demand roadside assistance, remote door unlocking, stolen vehicle assistance and turn-by-turn navigation. Adaptive cruise control with low-speed automatic braking is standard on Platinum and optional on Premium.

In Edmunds brake testing, an XTS4 came to a stop from 60 mph in 123 feet, which is average for a car in this class wearing all-season tires.

Available safety features include blind-spot monitoring, lane departure warnings, forward collision warnings, rear cross-traffic alerts and a vibrating driver seat that alerts the driver to an impending collision on either side of the vehicle.

In government crash tests the 2014 Cadillac XTS earned an overall rating of five stars, with five stars in overall, frontal crash and side crash tests, and four stars in rollover tests. In IIHS tests, the 2014 Cadillac XTS earned the highest rating of "Good."

As imposing as the 2014 Cadillac XTS seems at the curb, it's a distinctly smaller car from behind the wheel. Thanks to the standard adaptive suspension, trusty steering and responsive engines, the XTS manages to shrink its big body around the driver.

Yet this full-size luxury sedan's capable handling is more of a pleasant surprise than anything else. Comfort is king for a big Cadillac, and the XTS doesn't disappoint. The same adaptive suspension that keeps the body composed in corners provides a firm yet buttery-smooth ride on most surfaces. It's far from the floaty Cadillac land yachts of yore, but when you're rolling down the highway in an XTS, there's no doubt you're in the lap of luxury.

As for the new XTS turbo V6, it really transforms the driving experience. Not that there's anything terribly wrong with the base engine, but the standard XTS lacks the confident oomph of traditional Cadillacs. The muscular Vsport, on the other hand, feels more like an old Caddy V8 off the line. Springing for the upgraded V6 is a no-brainer if power is a priority.

The Cadillac XTS gives you the kind of passenger volume you expect from a nearly 17-foot-long luxury sedan. Rear riders in particular will appreciate their ample accommodations. With 18 cubic feet of capacity, the XTS's trunk is one of the biggest on the market, but it's unusually narrow, so golf clubs will likely need to be creatively positioned alongside other luggage.

Of course, we're used to Cadillacs that give us room to stretch out. The XTS's futuristic dashboard, though, is something else altogether. The optional gauge cluster display is beautiful, first of all, with all manner of driver-configurable options. Then there's the CUE ("Cadillac User Experience") interface, which integrates audio, phone, optional navigation and OnStar functionality into an 8-inch touchscreen display. Those familiar with smartphone and tablet interfaces will feel at home with CUE's touchscreen, as it uses similar touch, swipe and pinch commands.

There are also auxiliary touch-sensitive buttons beneath the touchscreen, however, and they're a mixed bag. These buttons help control the stereo and climate systems, and they can be a challenge to use if you're trying to drive at the same time. For efficient operation, you may need to look down at the panel for a bit to see what you're pressing, which of course requires you to take your eyes off the road. As slick as this control panel looks, we're not convinced that it's practical enough for prime time.