I bought the Roku and with plex it can play music and photo together, so that is a plus. It is not possible to change the playlist of the music while viewing photos. You need to start the music first and then the photos. But once you know it is not really a issue. There are however buttons for it, so why don't use these for that for skipping to the previous or next music number.
There is no zoom on photo's, no black background and most importantly no control of the slideshow interval. That last is really a feature that should be there. Also it is impossible for new users to know what are the limitation of each device since on smart hub plex the speed could be changed as i posted earlier.