The pathways are big reason. They are wider at USF, so they have more space to work with. Another is the fact that USF is just blank building, so they can put pretty much any king of theme, color, lighting, you name it. The ONLY area at IOA that lends itself well to HHN is JP cause of all the trees. Otherwise its hard to make an area full of Marvel characters, Rocky and Bullwinkle, and Seuss scary.