Looked around myself and I think the Meisterschaft is a beast. However for me it is too much and too loud. I want my F10 550i to sound sporty and have that growl to it but not wake up the entire neighborhood and scare grandmothers each time I pull up to or take off from a stop light! After listening to a few clips and searching extensively I went with an Eissenmann Race exhaust. Have had them on my M3 and X6 and they were very nice! Refined but sporty and definitely distinctive enough to change the sound and demeanor of the car.
There are some others out there too Supersprint and some folks have tried to adopt Remus (who don't make a system for the 550 yet) and others have done some custom systems too. Take a look around and see what floats your boat.