The alpha navigation feature is quite neat, but it could perhaps benefit from a slight re-design. If you–let’s say–want to get an artist starting with GOL, you press the ABC button to bring up the navigation, and press G, making a subconscious note of where the letter O is, which you want to type next. But the location of O moves, because not all letters are likely to be present in any given library following G. Therefore you have to spend time looking for where the O is now. The same thing repeats for the next letter.
This makes the operation slower than necessary, because the user can’t predict the next state.
A suggestion would be to have a full character list always present, with non-existing letters inactive (“greyed out”); in order to enhance the input speed.
That said, if the alpha nav just replaced the scroll bar without taking up anymore screen space then I’d be happy with having a single row of alpha characters …
Provided they are not that small to make selection difficult on table sized screens.