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.
Current: 2016 F80 M3 6-Speed | SO | AB XT1 | ZCP | M Performance Suspension | GC Camber Plates
Previous: 2009 E90 M3