4.2 R8 for a day...

So I had the chance to take an R8 for the day yesterday. It was a 2014 4.2 automatic. I have had my RS4 for a year now as a daily and I have wondered about the v8 R8 for some time. The car was pretty awesome, handled well, power was nice with the auto trans. Compared to the RS4 it really didnt seem that much faster. The only thing about the car that would get old to me quick was people constantly taking pictutes at every traffic light, and kids saying nice car man or smoke the tires. So ill get to the real question, how do they stack up against each other? 1/4 mile stock vs stock etc? Is it really a better car? Looks factor id take one over my RS4 in a second, just curious about statistical figures for conversation sake.