I have an extensive digital music collection which I play from so can offer some thoughts. I have a 10 inch tablet which I've played from in concerts and organ crawls. Advantages include
- ability to carry all your music around with you in one device
- pdf music books can be edited to include just the pieces you play, and they can be joined into a single document. So I would take just the pages I am playing, merge all the pieces together and play the entire recital from a single pdf file, no searching for the start page or changing music books between pieces
- variety of mechanisms by which page turns can be executed - swiping the screen, mouse click by attendant, thumb or toe piston if linked by some mechanism
- ability to annotate pdf music files and thus tailor to the performance, e.g. single set of piston marks rather than lots of pencil marks and rubbings outDownsides
- main downside is that you have to turn pages twice as often as you would if you use sheet music
- depending on speed of tablet, page may not "turn" instantaneously
- may experience issues when turning from portrait to landscape orientated music when using mouse as you have to click in a particular part of the screen to turn
- occasionally page doesn't turn or you get two turns at once
- most tablets are 10 inches or less, which is a bit small to read, you really need to be 13 inches screen size to match an A4 paper page
- valuable and not very thief proof
- software can crash and hard drive can corrupt
- make sure battery is fully charged before you start your recital (most tablets will last several hours)!
I also take my tablet to recitals to follow music - often I've already got the repertoire on file but if I need to look something up that is not in copyright I can look online during the concert at the usual sites, especially imslp.
My own feeling is that the advantages of playing from a digital scan of the music outweigh the disadvantages, but at home I practice on a Hauptwerk instrument that I built which incorporates a 26 inch music desk monitor, mounted behind a Perspex screen with a conventional book holder below. This enables me to play from a digital music file or from paper music if I want to use a music book without scratching the monitor screen. 26 inches and above are big enough monitors to display two pages at a time, whether portrait or landscape orientation, and I have the choice of thumb pistons or toe pistons for forward and reverse. This works so well that when I'm out and about I can find it hard not to kick where I am expecting the page forward toe piston to be and have to remember to swipe my tablet! I would absolutely wholeheartedly endorse having a large monitor in the place of the music desk and a page turn facility - now that computers have been miniturised to fit onto widgets the size of memory sticks, so long as you don't have a mechanical action in the way, you could very easily set up a large monitor in the position of the music desk with a miniture PC attached for £300 or less.
Having a practice organ connected to the internet is a hugely valuable teaching aide - I can look up and find new repertoire, and sit at the organ bench and watch and listen to Youtube recordings of pieces as I learn them to pick up different styles of interpretation, check for wrong notes and even observe fingering and toeing. This is as true of a home pipe organ as a digital organ.
One further advantage of this approach from the perspective of learning new music is that you can add a blank page to the start of a piece of music. and thus shift all even pages to odd and vice versa. That way, any awkward page turns can be shifted by a page so that they go from the left hand to the right hand page, and you can practice the entire passage either side of the turn without having to be distracted by turning a page. I have posted a number of recordings on Youtube which show my pageturning technique.