This is by no conceivable stretch of the imagination a warts and all form of conclusion.
In fact, it isn't even a conclusion at all. But seeing as how I've driven both the Porsche 918 Spyder and McLaren P1 now, well, it would seem churlish not to offer at least some form of opinion about how two of the world's three maddest hypercars compare with one another.
So here are the facts, plus a bit subjective stuff thrown in for good measure.
One, the P1 is faster than the 918. Everywhere. On paper it looks close enough for there not to be much difference in the real world. But in that real world the McLaren feels of-another-solar-system quicker the Porsche. It feels as fast as anything I've ever driven to be honest, including Honda's 2007 F1 car, whereas the 918 feels merely very fast indeed.
Two, the P1 generates so much downforce in third gear and beyond when it's in Race mode that the 918 driver will not see which way it's gone around a circuit. They, McLaren, reckon the P1 generates as much as 5g of cornering force around corners like Blanchimont (at Spa) and Copse (at Silverstone), and having driven it around Bahrain, I believe them. The 918, on the other hand, doesn't even get close to that sort of grip.