I work with computers all day (translator, writer ...) and I love my e-book reader and I also care about the environment and ALL THAT, but I still definitely prefer to print my note sheets out and always read the music from paper. Why? Because I need to scribble a lot when I work with a new piece. Fingering etcetera. Sometimes I tend to make recurring mistakes (no sh*t?) when I sight-read and then I have to circle some tricky notes and parts that need special attention. For example, yesterday evening I discovered that a note, which I have read as a G for weeks, in fact is an E flat ...

It is hidden in a jungle of other notes, that is why I had misread it. So, BIG black circle there, because now I must re-learn that bar.
So, I find it very difficult if I cannot use my pencil ... therefore I need real paper, that also can stand an eraser a couple of times.
My opinion.