Decibel Comparison

I did search the archives here and on Pelican and there was plenty of personal opinions, but my basic questions remain :

Is a Dansk Sport exhaust louder than a Bursch ? Do either of them offer any noticeable performance improvement over stock ?

I am replacing my stock exhaust on the E (its done). I am looking more for performance than sound (I was not unhappy with the stock sound). I know what the Bursch sounds like on an early car, but have no experience with the Dansk. The Dansk does have the advantage of the stock look.

Any experience is appreciated. TIA