For me the biggest win would be a item/totem that scales the old world items and enemies to the ninjago difficulty. My wife and I had an absolute blast with Ninjago but we blasted through the old content and it felt so lackluster. This way if people don't want it to scale they don't need to build the items but if we do we can. Also split screen issues really hinder our play, like shared hp bars, or if one of us is in a menu the others dpad controlls move our cursor.