Jaguar’s supercharged XF entered our long-term driving program one year and 21,171 miles ago, arriving with promise and potential muted by questions. Would this larger-than-luxury midsize—delivered in the middle of the brand’s purchase by India’s Tata Motors—negate buyers’ hangovers from a decade of parts-bin cars wearing recycled Detroit bodies? Or could it possibly be just the kick-start that the marque so desperately needed to avoid extinction?

After a full year in our editors’ hands, the XF has soundly distinguished it-self for reliability, durability, and total value (stickered from around $50,000 to $63,000). And with excellent sales numbers, the XF (in both normally aspirated and supercharged versions) truly represents Jaguar’s triumphant escape from the automotive wilderness and a rededication to its 70-year-plus tradition of producing fast, beautiful cars.

Power from the 420 hp, 4.2-liter supercharged V-8 engine is instant, exhilarating, surging propulsion, from zero to 60 in 5.1 seconds—the kind of force that gets an experienced driver out of trouble, not into it. We continually used the car’s quickness to navigate through rapidly moving walls of freeway traffic, and small holes between vehicles translated to large gaps while moving at speed. The XF’s stylish 20-inch wheels, 6-speed paddle-shifted automatic transmission, blind-spot monitors, and back-up camera proved that this Jaguar sweats the small stuff while continuing to lead the sports-car pack. Noted one staffer, "Finally, a luxurious car from Jaguar with a true sports-car attitude. It even has a sport mode. I think the Jaguar XF will lower the Jaguar driver’s average age."

"Being a Jaguar traditionalist, I am still undecided about the exterior styling," wrote another staffer in our logbook. "But it certainly has a distinctive appearance." Indeed, the XF’s well-proportioned lines, front-fender gills, and doe-eyed headlights kept the admiring glances coming. But the high hood and enlarged, even ungainly, grille seemed a little out of character with the rest of the car.

There is considerable froufrou in the XF: Ambient phosphor-blue lighting accents the doors and dash; an aluminum hockey puck rising from the dash serves as the gear selector; a start-stop button pulses arterial red before ignition, as if with the car’s heartbeat; heating and cooling vents revolve and open upon starting.

We thought these novelties might wear off before the second stop for gas. They didn’t, though, and luckily all this delightful nonsense will find its way into even better Jaguars to come. Except, we presume, the touch-sensitive button for opening the glove box, whose responsiveness seemed to change with every jab of the finger. (Jaguar, however, has addressed this minor issue on the 2010 XJ flagship sedan.)

With gas prices swinging between $4.49 (Santa Monica, September ’08) and $2.01 (Phoenix, last March), it was impossible to log a fair dollar amount for fueling the XF over the year, but we were able to measure an overall fuel economy of 22.5 mpg—right at the EPA estimate for highway driving, and far better than the city estimate of 15.

Despite some furious driving, including hefty handling by some 50 citizen judges at Robb Report’s Car of the Year contest in November, the XF survived its 12-month tour with zero breakdowns. In fact, the only flub was my failure to remove the remote fob from the automobile while it was parked in the garage; the fob continued to chat up its parent computer and drain the car’s battery—twice.

Many sport sedans are engineered with a rear track one inch wider than the front, which improves handling. In the XF, the rear track is almost two inches wider, which may explain why several drivers located so many curbs that insisted on reaching out to grind the lovely rear alloys.

We found ourselves wondering why, when Jaguar traditionally uses an "R" to distinguish its supercharged racing-performance models, the supercharged XF did not earn that designation. As it turns out, Jaguar was being canny, reserving its elite logo for the 2010 XFR, which features a brand-new 5-liter V-8 that delivers 510 hp for a zero-to-60-mph sprint of 4.7 seconds. That is Maserati and AMG country. That is being shot from a cannon.

You can definitely see the XFR coming, with its Robert Mitchum swagger, hood vents, and front grille carried over from the XF. Picking up where the XF left off, the XFR is head and shoulders above any other Jaguar ever made, and has enough heart and soul to more than take on the German competition.