It works!
It works exactly as advertised. Of course, as expected it takes a minute to load a book and only turns 10 pages back and forth. But lately I have been practicing one music piece out of a book. I found it very useful just keep that book loaded as I work on the piece over and over. To play something from a different book, I remove the unit without unloading the book.  Major benefits are that it holds the book so you don't have to overlap other books on the sides to keep it in place, and it reduces the wear and tear (literally) from flipping pages back and forth dozens of times.  A drawback is reloading if you regularly play more than one piece from the same book. I think it is worth the $99 price.
Rating: 5 stars