situation is insignificant is 100% false. I even looked at the last posted local auto-x results, and there was a 1/1000 second difference between some drivers.
When I read the GRR article last year I was kind of surprised they came to the conclusion they did using the data they got. Look at some of their tire tests - they would claim a "clear winner" if a tire has an average lap time of .09 seconds faster than another.
But yeah, like I said before, I can feel a difference personally, but I can't argue with real-world tests like GRR so my opinion changed. But it's really moot since I'll always buy light wheels regardless.