Weight is what it brings. Or rather, as you'll probably know, a lack thereof. The Spider adds just 46kg to the weight of a 570S Coupe, and that's all in the roof mechanism and panels (i.e. none of it is chassis strengthening). That means a lightest dry weight of 1,359kg for the Spider, a huge amount less than the R8 (1,612kg dry), 911 (1,670kg ready to go but without driver) or AMG (1,660kg to the same spec as the Porsche). And, well, light cars tend to be the most dynamic ones, don't they?
With a weight gain of just three per cent - that would be a good return after Christmas - the same power and, well, very little else changed from the Coupe, the Spider makes some very favourable first impressions. Assuming, of course, you can stand the shame of being a whole tenth slower to 124mph.
Speed doesn't Matter
The joy of recent McLarens, however, has been their ability to entertain and involve at half that speed. Heck, at a quarter of that speed. The Spider is no different to those cars, proving that a good sports car is as much about the experience as it is outright speed.
Crucially none of that is affected in the switch to Spider. If anything it's more engaging now because of the open air around you - accessible in just 15 seconds, don't forget - and the racket from behind. Sorry, sound from behind. It still isn't the most thrilling soundtrack, the McLaren's, blaring and fizzing through its rev range rather than singing. It's very far from a bad noise, but there's little doubt either that an R8 or AMG GT, or even an F-Type SVR, offers considerably more sonic entertainment. Perhaps you don't care, though noise is an important factor with convertibles - just look at the discussion around the 718 Boxster...
What there can be no debate on however is just how ludicrously rapid the 570S Spider is. Again that will be because of the minimal weight gain, and anything that can hit 124mph in less than 10 seconds is very, very fast. In the middle of the last decade 580hp qualified your car as a big boy supercar (Lamborghini Murcielago), yet here we are in 2017 and a car with 10hp (and a hell of a lot of weight) less is very much a 'junior supercar'. Madness. Whatever, the Spider is staggeringly quick and matched to the dual-clutch gearbox about which there can be very few complaints. There's even the odd 'BANG!' from behind when the exhaust gets really hot, which is exciting. Ultimately the powertrain of a Ferrari 488 feels yet more special again, though we're working in the very upper echelons here.
Thing is, once driving at speeds more befitting of a new 200mph supercar (while trying to keep a hungover Dutchman asleep in the passenger seat - long story), the McLaren might be better than the Ferrari. Might be. That carbon tub simply means that nothing is sacrificed dynamically, to the extent that exactly the same spring, damper and roll bar settings are carried over from Coupe to Spider. Which therefore means you get the same superb precision, agility and involvement with this car; regardless of Ferrari's efforts, the same transfer doesn't quite happen from 488 GTB to Spider.
There are problems, though. There have to be. Despite McLaren's persistence with the Brake Steer technology, there's a suspicion that a locking rear differential would give it more precision on corner exit. Where in something like a 488 - that car again - you can feel power being distributed across the rear, in the McLaren there's a greater sense of just the inside wheel being braked, quelling any greediness with a more heavy handed approach. A minor concern for the vast majority, though it is there.
720S, though for now it feels below par. It's slow to respond, the graphics aren't brilliant and the instructions aren't all that clear. Could Apple CarPlay or Android Auto perhaps be incorporated soon? Certainly it's far more of a real world issue than whether continuing with an open differential is fun enough... Speaking of real world, the seats in our test car were very uncomfortable for both the driver and passenger over six foot. Curious.
Those flaws aside, the Spider can be considered a resounding, thrilling, brilliant success. As the old adage goes, anyone can make a fast car but it takes skill to make a fast car go slowly. Or something along those lines. That the Sports Series McLarens are already so absorbing at all speeds is arguably their greatest success; with the Spider that depth of talent has been complemented by an additional layer of drop-top supercar glamour and excitement. It's fantastic.
MCLAREN 570S SPIDER
Engine: 3,799cc, twin-turbo V8
Transmission: 7-speed SSG automatic, rear-wheel drive
Power (hp): 570@7,500rpm
Torque (lb ft): 443@5,000-6,500rpm
Top speed: 204mph
Weight: 1,486kg (DIN, inc. 90 per cent fuel)
MPG: 26.6 (NEC combined)
Price: £164,750 (As tested £204,540 comprised of £3,560 for Sicilian Yellow paint, £2,190 for Dark Palladium roof, £2,690 for 10-spoke lightweight forged alloy wheels, £1,140 for Stealth wheel finish, £910 for Liquid Black brake calipers, £3,370 for Sports Exhaust, £460 for Stealth exhaust finisher, £2,570 for Jet Black and Sicilian Yellow designer interior sport design 6, £2,550 for carbon fibre interior components, £5,740 for MSO Defined carbon fibre rear deck and tonneau cover, £4,090 for security pack, £7,280 for Luxury Pack and £3,240 for Carbon Exterior Pack 1)