I've got a David Clark H 56 ANR. Great in fixed wing pistons/turbines and anything with more than three blades (AS 350 etc) But it's bloody awful in two bladed machines (Bell 205/206), you get a funny whooping sound in your ears much like pressure changes so I switch it off.
I know what you mean about the battery box hanging on the cable but I fly so many different machines it was the only option for me...thats life!