Like AndyC, I sat in the car for several fast laps of Dunsfold with one of McLaren's "tame" racing/test drivers and also clocked around 1:24 from a rolling start (start finish line was half way round the laps that we were doing). Can't believe that 10 plus seconds could be shaved off that time, even with new rubber and pads.
Love to be proved wrong, but lets be realistic, not many of us could even get near 1:24 with our own skills, so its all a bit academic and Top Trumps talk.
Its how is goes and handles on the roads, in our hands, that really matters.