Stormblood as a narrative is not super strong, like most people have said. But I simply adored Hien and I think he's criminally underrated and he's easily a favorite character of mine. Zenos is also a favorite; I don't think I've ever thought "this villain is crazy" from the bottom of my heart before but by the end of the main patch I truly was just like "WHAT THE FUCK ARE YOU TALKING ABOUT". He's great!

The dungeons and trials are a load of fun and really come into their own now that they lean more on standardized mechanics involving positionals and AOEs rather than you knowing the gimmick of the dungeon. Finally, the maps (namely the Ruby Sea!) are pretty to look at and much easier to navigate than Dravania was.

Heavensward is way stronger than Stormblood narratively (and I really can't stress this enough) but Stormblood offers the more enjoyable 'gaming' experience imo.