There's a risk in bending to the will of a fashion trend versus sticking with a classic design. When the Infiniti Q70 debuted in 2011 as the M sedan, it was unique for its organic flowing shapes and unconventional cabin materials. In a short four years, the style of Infiniti's largest sedan is looking more and more out of date.

Outside of style, the 2015 Infiniti Q70 also suffers from other maladies that place its competitors in a more favorable light. As a luxury sedan, the Q70's ride quality falls well short of the type of smooth isolation that other cars provide. Normally, we'd expect this kind of stiffness to result in more athletic handling, but the vague behind-the-wheel feel neither inspires spirited driving nor confidence. Optional sport packages tend to further compromise comfort with little return for the driver.

New for this year, the lineup gains a new Q70L long-wheelbase model that greatly increases rear legroom. Considering that the standard Q70's rear seats are already quite accommodating, this new model seems a bit unnecessary. With a lack of available rear-seat amenities found in other long-wheelbase luxury cars, the Q70L's existence is downright puzzling here in the United States.

Further compounding matters is the strong competition from competing luxury sedans. We recommend checking out the venerable BMW 5 Series and Mercedes-Benz E-Class, as well as the Audi A6, Cadillac CTS and Lexus GS before committing to a 2015 Infiniti Q70. We're confident that you'll find, just as we have, that the Q70 comes up short and is quickly falling out of fashion.

The 2015 Infiniti Q70 is a five-passenger midsize luxury sedan that is offered in 3.7 and 5.6 trims that correspond with engine sizes. Both are available in Q70L long-wheelbase versions, which are classified as large sedans. A Q70 Hybrid is also available, but only in short-wheelbase form.

Standard features for the Q70 3.5 and Q70 Hybrid include 18-inch wheels, automatic LED headlights, LED foglights, auto-dimming and power-folding mirrors, a soft-close trunk lid, automatic wipers, a sunroof, cruise control, dual-zone automatic climate control, leatherette premium vinyl upholstery, a leather-wrapped steering wheel and gearshift knob, a power tilt-and-telescoping steering wheel, eight-way power-adjustable heated front seats with two-way lumbar, driver memory functions, keyless ignition and entry, a universal garage door opener, wood interior trim, a rearview camera, Bluetooth phone connectivity, a 7-inch infotainment display and a six-speaker sound system with a CD player and a USB/iPod interface. Q70 L models add soft-close rear doors.

Upgrading to the Q70 5.6 adds the Premium package (optional on the 3.7) that includes a navigation system, voice controls, traffic reporting, leather upholstery, cooled front seats, a heated steering wheel, rear parking sensors, a multiview parking camera system with moving object detection, an 8-inch display, Infiniti Connection telematics service and an upgraded 10-speaker Bose audio system with Bluetooth streaming audio.

All subsequent optional packages require the Premium package.

The Deluxe Touring package includes a premium 16-speaker Bose surround-sound audio system, a power rear sunshade, upgraded leather upholstery with added seat bolstering, silver-powdered wood trim, a simulated suede headliner, additional interior padding and a leather-stitched gauge pod. The Technology package (requires Deluxe Touring on 5.6 and Hybrid) adds adaptive headlights, adaptive cruise control, a lane departure warning and prevention system, forward and rear collision warning with emergency braking, a blind-spot monitor with intervention and an Active Trace control system that assists the driver in keeping the car on its intended path during cornering.

The Performance Tire and Wheel package (not available on the hybrid) gets you 20-inch wheels, all-season performance tires and upgraded brakes. The Sport package is offered on standard wheelbase models and includes 20-inch wheels, summer performance tires, a sport-tuned suspension, upgraded brakes, paddle shifters, sport seats, aluminum pedals, a leather-stitched gauge pod, a sport steering wheel and shift knob and unique front exterior styling. The Sport Touring package adds the 16-speaker Bose sound system and power rear sunshade to the Sport package items.

Powering the 2015 Infiniti Q70 3.7 is a 3.7-liter V6 that produces 330 horsepower and 270 pound-feet of torque. All Q70 models come with a seven-speed automatic transmission with manual shift control. Rear-wheel drive is standard, while all-wheel drive is available on non-hybrid models. In Edmunds testing, a Q70 with the V6 accelerated to 60 mph in 6.1 seconds, which is quick among rivals. The EPA estimates the Q70 3.7 will achieve 21 mpg combined (18 city/26 highway). The AWD model is rated at 20 mpg combined (18/24).

The Q70 5.6 uses a 5.6-liter V8 that's good for 420 hp and 417 lb-ft of torque. The EPA estimates 19 mpg combined (16/24) fuel economy for the rear-drive and 18 mpg combined (16/23) for the AWD. It reaches 60 mph in 5.2 seconds, which is similar to other V8-powered sedans in its class.

The Q70 Hybrid employs a 3.5-liter V6 that works in conjunction with an array of lithium-ion batteries that power a 50-kilowatt electric motor. Combined output comes to 360 hp and is estimated by the EPA at 31 mpg combined (29/34). It reaches 60 mph in 5.5 seconds.

Standard safety features for all 2015 Infiniti Q70 models include antilock brakes, stability and traction control, front-seat side airbags, full-length side curtain airbags, active front seat head restraints and a rearview camera. Buyers can also add options that include a lane departure warning and prevention system, a blind-spot warning and intervention system, forward and rear collision warning with autonomous braking and a multiview parking camera system.

In Edmunds brake testing, the Q70 with summer tires came to a stop from 60 mph in between 112 and 115 feet. These distances are a few feet longer than average for the class. Although all-season tires increased that length to about 120 feet, that's comparatively average for the segment.

In government crash tests, the Q70 received a five-star rating (out of a possible five) for overall and side-crash protection, and four stars for frontal-impact protection. The Insurance Institute for Highway Safety awarded the Q70 its highest  score of "Good" in the small- and moderate-overlap frontal-offset impact tests, as well as a "Good" score for the side-impact, roof-strength and whiplash protection (seats and head restraints) tests.

Most drivers will find the base 3.7-liter V6's power adequate, though getting up to speed or passing slower traffic does require a solid stomp on the accelerator. The resulting engine noise sounds strained and coarse. The more fuel-efficient Q70 Hybrid is a bit more powerful and represents a good middle ground in the lineup. Not surprisingly, the Q70 5.6 packs a lot more punch with its V8, but it lacks the pin-you-to-the-seat rush of power that other V8 sedans have.

In terms of ride comfort, the Q70 also comes up short. The standard suspension is stiffer than its rivals and has a tendency to point out every flaw in the road. Opting for the sport-tuned suspension or larger wheels further exacerbates this problem. It's also worth noting that wind noise can be tiresome, especially on longer road trips.

With the stiffer ride, a fair assumption would be that the Q70 would have more handling prowess, but the heavy and vague steering feel and the vehicle's perceived weight don't encourage spirited driving. While the car responds well to driver commands, it doesn't inspire confidence on a winding road. When it comes to ride comfort and driver engagement, competing sedans represent better choices than the 2015 Infiniti Q70.

For the most part, the Infiniti Q70's cabin benefits from high-quality materials and solid craftsmanship. The infotainment system may lack the eye-catching modernity of its rivals but its mix of physical buttons, touchscreen and a multipurpose control knob is at least intuitive and easy to operate. We like it, but tech-savvy folks might find it a little antiquated.

The Q70 provides a good amount of head- and legroom in all seats, allowing for adult-sized rear passengers. New for 2015 is the long-wheelbase Q70L model that further increases rear legroom, but the absence of typical long-wheelbase options make it feel oddly barren. There are no rear controls for climate or audio, nor are there amenities like heated and ventilated seats, footrests, a rear entertainment system or extra USB ports.

Cargo capacity for the Q70 and Q70 L tops out at 14.9 cubic feet, which is about average for midsize luxury sedans. The Q70 Hybrid's 11.3-cubic-foot trunk is smaller to make room for the batteries.