Sirhan Sirhan (or whatever his name is) at Moon Audio is full of Baloney, but what else is new. No, they don't. I own them both and they crack and distort in orchestral (classical) music during the fortes, particularly when the Timpani strike in full force. So, there...I've fought the battle and I have the scars to prove it!
Just curious, does the distortion go away if you turn down the volume? I'm trying to figure out if the clipping is happening in the input stage of the Burson or in the output stage.