I own a ///M135i an E92 ///M3 and a F10M M5. got and order in for an ///M4 (which I will rebadge M3
all I can say is that you'll never notice this issue at all. all cars both the ones with the engine sound amplification and without are noticeable. infact the M3 I put on the performance exhaust as it was too quiet.
I really suggest you wait until you experience it before you give it the thumbs down. I. know there will be a bunch of whinging fcukwits that will whinge all the same and then be first to post how they love the new car and the sound system is awesome.
I personally can't wait for the new motor.