Comments:
I fly a corporate aircraft with ship powered Bose headsets. I like the noise cancelling features and audio performance of Bose but unfortunately my head is not pointed to fit the way the headset folds, so I get hot spots. I bought the upgrade kit for the bigger head pad. It helps some but doesn't make the fit perfect. I also have David Clarks, I can wear them for hours at a time but they're not ship powered....
The new ear cups for the Bose are difficult to get on and keep on. They're firmer than the original ear cups and not as comfortable. I didn't use the microphone cover, I don't have a noisy environment.
All in all, the kit is ok, expensive for the benefit gained.