I never used it for sound, but it was extremely useful for rotation lock. One argument for the removal is that there is no space, but this could be fixed by using the iPhone style switch. Another argument is that it doesn't matter because it can be done in software. But this method is much slower, especially now with iOS 10. It's not an essential feature but I think it'll be really nice to have (like no camera bump on the 9.7" iPad Pro). What do you think? EDIT: A lot of people seem to be talking bout the mute functionality. Personally, I don't care about that due to the fact you can use the volume buttons. I'm referring to the rotation lock functionality.