The 750 horsepower tuned GT-R ends up dominating all the tests, what a surprise. It's the fastest in a straight line and the fastest around the roadcourse. Yawn. The meaningful comparison though is between the R8 and the 911 Turbo S.
Between the two, the Turbo S is the faster car in a straightline. The updates to the R8 V10 make it quicker and faster although not by much as Edmunds recently showed with test of it. Considering a stock 997.2 Turbo S recently went email@example.com in the 1/4 mile it is no surprise to see it the beat down the R8 in the drag race. Skip ahead to the 16:00 minute mark to see the drag race.
The R8 wins around the track though with a 1:16.2 versus the 1:16.9 for the Porsche 911 Turbo. Subjectively, the R8 is car picked overall despite being the slowest in a straight line. Sometimes its now how much power you deliver but how you deliver it. The R8 seems to simply be the most enjoyable to drive.