Yes I really do read them cover to cover and when I find something interesting I make a note of it. Perhaps I'm unusual in that I like reading manuals and documentation. For me it is part of my enjoyment of learning how things work.
I used to do this (stopped checking every manual but still do it for tech stuff with a bunch of features) and nowadays it pays off a lot for my hobby of electronic music production, reading manuals for the synths I want to buy helps a lot to visualise the potential.
