Internal sound is very good, but the outside is way off. It get's really annoying right before the Rev Limiter. On Min 1.46 at the corkscrew is the best example. Till 7500k rmp's it sounds good but above it just get's annoying loud and the characteristic Porsche Sound get's lost.
I heard the Car myself this Year at the Nürburgring and this High note wasn't there.