As someone who runs the KO arenas, it is just SO MUCH easier. Although you still need to start on a loading screen, it doesn't matter if it's a restart or a level enter. Although ending with the postcard is kind of annoying, the time itself is only the in game time, so loading screens and opening the chest don't count. (which is nice) I don't understand why the ending cutscenes have to count for other levels, that is kinda weird.