I'll second what Toyman! said.
Glad you mentioned OEM tires. A number of reviews of the MK7 and 7.5 GTi complained about the all-season tires VW had on the car that gave up way too early and spoiled a lot about what was a very good chassis. I agreed. The Bridgestone Potenza RE97 AS that came on my car had so little cornering grip -especially in the wet- that I researched them to see what was "wrong" with them.
Turns out, nothing was technically wrong with them, and the simple answer was that they were developed almost solely for delivering good gas mileage, which yeah, they delivered on.
When the MK8 GTi was delivered for reviews, many people remarked about the serious upgrade in tires this time around, a few outlets even using words like "cheater tires." The tires no doubt helped the various lap times tumble, probably more than the usual bump in horsepower and torque, and some chassis development...I have no doubt it all helped, but the big takeaway seemed to be the rubber that hit the road.
I appreciate the way y'all approach the topic of testing and the data logging, as it does provide interesting insight.
This post is long enough, but you mention a magazine that may or may not go by the initials of R&T. I remember reading that mag back in the early 1980's when ABS was a new thing and there was "enthusiast" pushback about safety nanny intervention, it interferes with driver involvement, and everyone was a Driving God who was simply better at braking than some artificial ABS system would ever be. (as an aside, aren't you glad enthusiasts got over those types of tired arguments long ago?)
Anyway, to *prove* humans were better than computers, that magazine had two guys test a car with and without ABS. And yes, those two dudes were able to threshold brake about 2 ft. shorter than the car with ABS did.
That mag proved its point once and for all, case closed.
Oh, I'll just mention something even though it's likely of no importance, really, but those two dudes were named Paul Frere and Phil Hill. Just your usual "Everyman" drivers who happened to win a lot of sportscar, endurance, and F1 races, and stuff. But I doubt that impacted the test in any way.