Very boring 2 minute clip. Both cars were driven around a track and the BM was 6/100 faster (because it is lighter and handles slightly better). Other than that no real comparison of the two cars. Certainly has not put me off the S5.
These kinds of lap comparisons are pretty much useless -- if any one of us took 10 separate laps with a vehicle we'd get 10 different times, each plus or minus a few tenths of a second.
Doing one lap with an Audi and one lap with a BMW doesn't really prove much. Also, not many people can master the characteristics of a vehicle in a matter of minutes.
They're pretty much even on track performance, but even if the BMW is slightly quicker around a track, who really cares? A chipped EVO or WRX is probably even faster but are still tin cans. I would take that stuff as only one factor in judging a car.
The S5 has more than sufficient performance with sure footed traction, crafted interior, elegant good looks, and more exclusivity than a 3 series. It will turn more heads for sure. Yes it's a few grand more than the 335 but so what... these aren't economy cars, there will be some price differences.
The days of the 3 series being head and shoulders above the competition are over. Audi, Infinity, Lexus have all improved their offerings significantly. I'll go with Audi because I much prefer German engineering and design, and a car like the S5 is just such a beautiful package.