I TOTALY AGREE that PCM interface and software are at least 5 years before in terms of design and function....

BUT

1) you can deside which will be the order of appearance for CD/Radio/NAV or other interface from the PCM set up menu
(check manual) You can do many things with the way the come up your screen when you open it up

2)there is a MUTE button that can be used simularly
JUST choose the AUDIO panel scrol the pointed selection down to the mute button, leave it there, and when needed you JUST push the button/scroller and the sound is MUTED !!!

IT a solution if you want to use mute frequently