Just FYI, you can mouse click on the art area in IV/Play to move between art types, or you can jump directly to them w/ alt-1-0 keys if you need to. I designed IV/Play to be more keyboard and desktop centric as that's how I used MameUI and now Mame baseline's UI.
◾Tabbed graphics extras pane. Stock MAME uses an annoying arrow system that forces you to cycle through each piece of artwork in sequence. I would miss this the most. It keeps me from wanting to use IV-Play as well.