Finally beat this last week. Definitely the best game I've enjoyed in some time. Loved the turn-based mechanics and customization options with the Pictos and Luminas that really open the gameplay up. Story took some wild turns for sure, but I think the balance between the gameplay and plot was very well handled. The turn order reminded me of FFX, which was definitely my favorite part of that game, and it was fun playing around with different combinations of moves, parties, etc. to set up some wildly good engines, etc.
My one complaint, and this is kind of self inflicted, is that I ended up being way too overpowered for the final boss by doing all the Act III sidequests first. To anybody reading this, I would recommend doing the final boss as soon as it becomes available. Thankfully the game also does give you options to increase the difficulty, etc., so again it's less on the game than on me, but YMMV on if you enjoy curbstomping the final bosses or not.
Still have to fight that one optional boss and do NG+, both of which I'm looking forward to!