Just this past week I was recording a forthcoming episode of my podcast with Chris Russell (which should be posted within the next few weeks) on working with digital scores. We got talking about stand alone sheet music reader devices, in particular how previous devices were made instantly irrelevant when the iPad came out.
Click the link below to read about a new device in this class, the Gvido Digital Music Score. The article goes into depth about the technical details of this device. I still cannot see how something like this is going to take off when even the top of the line iPad Pro is only hundreds of dollars cheaper and can do way more. I have a Kindle Paperwhite and I do think that E Ink is beautiful and far easier on the eyes during extended lengths of use. Still though, I think I would choose my iPad over this any day of the week.