+1 for the factory Stage 1 pipes. They are certainly loud when you're "getting on it" a bit, but I don't find them objectionable during part throttle cruise.
I'm sure the factory pipes are fine, but some of the setups I've heard on M3Ws are frankly ludicrous. One came through Stroud last year, I have no idea who it was, but is was ear-splittingly loud, I'm surprised it didn't break any shop windows. From the comments people were making I don't think the locals were impressed.
