Stormblood's biggest boon is it's worldbuilding. Save for the side story going on with Ul'dah, Heavensward was almost entirely focused on Ishgard. Stormblood, however, brings you across the planet to new continents to liberate a foreign nation of the big bad nazis, just so you could get them to help you liberate ANOTHER foreign nation, once again, on the other side of the planet. The story feels like it drags on for a bit too long in some parts though.