Not really digging the sounds myself, sounds to low and throaty, too Detroit and not enough Maranello. However, I love the idea of a tuneable exhaust sound. It suits me and suits the nature of the car perfectly (very user adjustable). Being able to lower the noise a bit for those long freeway jaunts and being able to hear your passenger or your tunes better is fantastic. Then when you want either:
-more aural pleasure
-more performance (maybe a bit better flow/slight hp gain)
Just flick the switch! Cool.
The M3 does have a built in system for this so it should be as simple as having manual control over the valve in addition to it being automated.