There's an idea that many trackday junkies hold dear, and that is that the GT3 is the best of the few cars that can truly excel on the track and still work well when driven to the supermarket. It's a tough thing to achieve, and rarely does any car do both well. However, if there's another contender for that role, it's the McLaren 720S.
Like the GT3, the 720S is a car that can play the pussycat on the road but is a rabid tiger on the circuit. Again, like the GT3, it's the result of lots of refinement in the smallest, seemingly-trivial areas of performance, and that gives it a competence that's hard to believe. Unlike the GT3, it is one of the fastest accelerating cars around. The powerplant is ferocious and will gobble up gears with a ravenous appetite. Yet it puts that power down without a hiccup. It's hard to believe that the GT3, with its wider tires, proper differential, and lack of turbochargers, doesn't put the power down quite as well.
What's more—the GT3 wears semi-slick tires, where the 720S is shod in Pirelli P-Zeros. That should account for some of the similarity in lap times, plus the tight confines of the track limit the McLaren's power advantage. Once the McLaren gets a chance to stretch its legs, it simply draws the horizon toward it. Astounding, but so is the way the GT3 can fire out of the corner on-par with McLaren. As different as these two cars are, and as big as the price gap separating them is, they both record similar lap times and possess levels of performance that would shame some racing cars from not too long ago.
There's one more trait these two share
Among many track day junkies, the GT3 is the unofficial king. Sure, there are pricier cars with more grip and more power, but the Porsche punches above its weight; a sports car with supercar performance. As the McLaren can out-accelerate a Veyron, has the panache of any million-dollar hypercar, and performs on track with the best of them, the McLaren seems to occupy the supercar realm while possessing the attributes of something five times the price.