All the 50th Anniversary edition 911 happens to be is a 991 Carrera S (offering a wider body) with the optional power kit standard. The naturally aspirated 3.8 liter flat-6 is bumped to 430 horsepower thanks to a new intake, cylinder heads, camshafts, and tuning. It is no match for a 5.0 liter supercharged V8 with 550 horsepower and gobs more torque. Why not use the 911 Turbo instead Motortrend? Pricing? Who cares? These are $100k+ cars anyway.
The power disparity despite the 911's roughly 500 pound weight advantage is clearly evident in the acceleration figures. The F-Type R gets to 60 in 3.6 seconds to the 911's 3.9 seconds. The F-Type R gets through the 1/4 mile in 11.8 @ 122.3 to the 911's 12.2 @ 115.4. Yes, the 911 does admirably for a naturally aspirated 3.8 liter showing great efficiency going up against a blown V8 but the F-Type R just has much more raw grunt on its side.
Power isn't everything and this matchup could be more even but what about the handling, braking, feel, etc.? Both cars feature ceramic brakes but the 911 courtesy of its rear bias stops in a shorter distance from 50 miles per hour by 5 feet. Despite the Jaguar's wider track by three inches the 911 pulls more on the skidpad at 1.00g to the Jag's .94g. Figure eight numbers have the Porsche a tenth of a second ahead at 24.4.
So which is the better car? To be honest, these are two spectacular vehicles. It comes down to a personal preference of finesse or brute force. MotorTrend describes the Jaguar as a British Corvette and that makes some sense. It is bigger, heavier, and beefier than the Porsche. The 911 however feels lighter on its feet (it is), offers more grip, and is centered around the driving experience over brutish torque.
The cars have different personalities and the better car is the one with the personality that fits your own.