Great job on the conversion!
Back in the day, I had a 1973 Ford Maverick (before they required those hideous 5-mph add-on bumpers in 1974) with a 302 inch V-8, but it only had a single exhaust. When I moved to northern Cali, I promptly hit the Midas muffler shop in Mountain View and had them chop my single exhaust into a dual exhaust with highly rated, free-flowing glass packs! Sounded so much better, and I loved it!...As I know you love yours.
On a side note, My son's girl friend has a 330i and I also suggested she try supercharging it, but I don't know how much of a power gain she would achieve. Correct me if I am wrong, but I do think it will boost the torque considerably if she supercharged the 2006 330i N52 engine.
Back on topic: Really clean!