The Nissan GT-R is what is known as a halo car. Such vehicles usually sit, somewhat unobtainably, at the top of an automaker's lineup, rife with domineering capabilities. Their existence at a brand's pinnacle is intended to cast a glow on the rest of the marque's offerings. Thus, the GT-R's outrageous speed, aggressive appearance, and otherworldly handling prowess are to provide buyers (or potential buyers) of more pedestrian Nissan offerings with a sort of trickle-down street cred.

But there is nothing trickly about the new, improved, and up-powered 2015 Nissan GT-R. In fact, in its top-notch, racetrack-prepped – but street-legal – Nismo guise, this muscular and technologically sophisticated $150,000-ish sports coupe now churns out nearly five Nissan Sentras worth of horsepower and enough grip to run around Germany's famed Nürburgring racetrack in record-setting time. If this carbuncular and resolute rapscallion casts any kind of halo, it's one that is thick with the black smoke of melted tires.

We found this out firsthand during some recent hot laps around Tokyo's Sodegaura Forest Raceway. The Nismo grabs hold and doesn't let go. And it's extremely purposeful, not only in terms of its prodigious output and road-dominating tenacity, but also visually, adding to its already aggressive visage and silhouette-exclusive (and functional) carbon-fiber wings, gills, and appendages up front, out back, and along all of its many origamic edges. No one will mistake it for anything else – except, perhaps, an apex aqueous predator.

For supercar consumers who want ever so slightly less bite with their bark, the "regular" GT-R is a notch more genteel – if such a thing can be said of a car that accelerates to extra-legal speeds faster than a Porsche 911 Turbo and prides itself on a certain amount of appreciable abruptness. The outgoing car could be somewhat brutal on the senses: champing and aggressive, and coarse. The new car ups that ante considerably with available upgraded interior materials, including perforated semi-aniline leather and paint embedded with 24-karat gold flake.

This change comes through most clearly in the way the new car rides, shifts, and sounds. It no longer feels as though it is trying to crack your teeth and spine with every expansion joint and downshift, or deafen you with metallic grinds and whines. It sounds more musical and less mechanical. It's more . . . human. It, thus, cants noticeably toward the stately but rapid class of vehicles called Grand Tourers that the first two letters of its name are meant to represent, rather than the Racing part evoked by the last letter. We regretted a 1,000-mile road trip we took in the old car. We don't expect we'd feel that way about its replacement.

We'd never use the word refined to describe a GT-R. That is not its mission. But this car surprised us with its transformative strides in this direction. Starting around $90,000, it is now much more than simply a lot of performance for the money. It is a lot of everything. And it's thus one of the few halo cars that can honestly be called a bargain.

RELATED: Click on "View More Photos" above to see a gallery of the Nissan GT-R, then and now.