> Stone Age UI
"The Stone Age didn't end because we ran out of stones"
UI schmueye... I'm an Android user, but even though a Lollipop update has been waiting for me to install it for a few weeks, I haven't yet bothered - the current KitKat UI is just fine so I'll let good people on the internet test the update for me first. "If it ain't broke..."
OSX hasn't drastically changed for an even longer period of time.... and given the wailing and gnashing of teeth about Windows 8's UI changes (I'm still on 7), Apple must feel a little vindicated.
I'll leave it to iOS users here to comment on whether iOS has any major annoyances that need fixing.