Like others, I’m pretty miffed at that disappearance of the hardware volume control on the iPhone. The in-app slider is just too sensitive. It’s often difficult to get it to settle exactly on “1” for example (which is too loud now for some reason … another story).

A simple solution would be to add + and - buttons at each end of the slider like the bass and treble controls.  
 

Why don’t Sonos do that? Seems like a no brainer after the loss of the hardware buttons.