Doesn't sound bad. From the poor quality welds, I am assuming it's a pre-production unit. Still the craftsmanship seems extremely poor compared to the Akrapovic and many aftermarket exhausts. That's quite disappointing coming from M.
2009 E90 M3 | SG | FR | 6Speed | Akrapovic Evo | JRZ RS1 | StopTech Trophy | Cantrell Brake Ducts