Last week we pitted two very exclusive grand tourers against each other and watched the Ferrari F60 America take victory by a single point over the new Aston Martin Vanquish Zagato. Going by the comments on our Facebook page , you guys seemed to agree with our assessment — while the Zagato Aston is the prettier car, the F60 has more potential in terms of performance and future value.

Earlier this week, we gave you a first look at the Mercedes-AMG GT R — a higher-performance variant of the the AMG GT, with more power and some aggressive new bodywork. But, Mercedes-AMG is hardly the first company to stick a big wing on a car, boost the power and tack a few extra letters to the end of its name. Porsche has been at this for decades, and the 911 GT3 RS is without a doubt the best of the breed.

Let’s see if the AMG GT R can knock it off the mountain top.

LOOKS: With its long hood and fastback roofline, the vanilla AMG GT is already a fantastic looking thing. The GT R amps up the aggression with flared quarter panels, a pronounced front splitter and sizable rear wing.

LOOKS: Visually, the GT3 RS has more in common with its GT-class racer brethren than it does with lower-spec 911s. The exterior enhancements are similar to that of the Merc, but with an even bigger rear wing (if that counts for anything) and a few new holes in the body to control airflow.

LOOKS: Go-fast variants of a pair of already beautiful cars. You can’t go wrong either way.

Mercedes-AMG GT R: 1

Porsche 911 GT3 RS: 1

ENGINE: The GT R gets a more powerful version of AMG’s 4.0-liter, twin-turbo V8 that produces 577-horsepower at 6,250 rpm and 516 lb-ft of torque from 1,900 to 5,000 rpm.

ENGINE: The rest of the 911 lineup has gone turbo-charged, making the GT3 the naturally-aspirated holdout of the range. Its 4.0-liter, flat-six engine produces an even 500 hp at a soaring 8,250 rpm and 338 lb-ft of torque at 6,250 rpm.

ENGINE: We love the Porsche’s old-school flat-six, but the GT R produces more power and has a much more useful torque band. It also sounds totally wicked.

Mercedes-AMG GT R: 2

Porsche 911 GT3 RS: 1

TRACK-DAY TRICKS: When set to race mode, a carbon fiber panel in the GT R’s underbody moves about 1.5 inches downward to redirect airflow. This puts an additional 88 pounds of downforce on the front axle, improving high speed agility. A rear axle steering system that adjusts camber within a 1.5 degree range improves low speed handling.

TRACK-DAY TRICKS: The GT3 RS also gets a rear-axle steering system and dynamic engine mounts that improve handling and throttle response while driving hard. Great stuff, but the real trump card here is weight. At the 3,153 pounds, the GT3 RS is about 275 pounds lighter than the GT R.

TRACK-DAY TRICKS: We’ll gladly give up active aero for a 275 pounds weight advantage.

Mercedes-AMG GT R: 2

Porsche 911 GT3 RS: 2

PERFORMANCE: Mercedes claims the GT R will sprint to 60 mph in an estimated 3.5 seconds and go on to a top speed of 198 mph. Mercedes hasn’t announced a Nürburgring lap time yet, but considering it was developed at the place, expect something under 7 minutes 30 seconds.

PERFORMANCE: The GT3 RS takes only 3.1 seconds to get to 60 mph — a figure that’s all the more impressive when you consider that Porsche is typically conservative when it comes to performance figures. In the right hands, it will lap the Nürburgring in an incredible 7 minutes 20 seconds.

PERFORMANCE: The AMG GT R should be an incredible car, but the numbers simply don’t stack up in its favor.

Mercedes-AMG GT R: 2

Porsche 911 GT3 RS: 3

The GT3 RS retains its place atop the mountain. Let us know which you would rather take to the track on our Facebook page .