Haven't seen all of it yet but so far the new dungeon and the Pixie-Tribe seems to be fun and the new Ally-Raid is really awesome. Still disappointed with the lack of new Gold Saucer Reward and the way longer PVP queing times though.
Also I still need to check out Hades-EX, the new crafting system, job changes like NIN or SMN and the rest of the Main Story as I stopped for the day right after the dungeon.