i've been playing this non-stop almost since I got it early.
I'm at the end of chapter 9 or 10 (Whichever one has the whole party together finally)
It's linear so far, as has been said, but for a damn good reason, the story is moving at a good clip, they're introducing mechanics, making you play EVERY character for a little while so you get a very strong feeling for each of their strengths and weaknesses. Unlike other FF's where I have a tendency to stick to the same basic people, with this I'm actually considering what they bring to the table.
The battles are all frenetic, and if you just spam auto-battle you're going to either a) get your ass kicked later game or b) succeed but like 2-3 star every fight. buffing/debuffing is a king strategy in this game and the key to fighting battles and winning them fast. Controlling one character and a good shift of classes during a battle will have you beating the at a fast clip and it's a hell of a rush. This is literally the first FF where skill seems to play a part. I hope later battles don't change that.
I like most of the voice acting except Vanille, jesus I wish she'd pick an accent and stick to it, everyone else fits. Treasure chests in rpg's always seem to shift, it's almost a non-issue.
Edit- Also keep note Auto Battle doesn't pick the best options, it may target weaknesses but that's about it, for example, Sazh auto-battle in buff class will still only use one buff at a time, despite having the ATB gauge large enough to cast a second buff. Or Commando will use a bunch of weak single skills rather than some more heavy hitting ones. It's almost always to your advantage to input commands, unless it's an easy regular battle (and even then sometimes it just kills them quicker)