I'm about 1/3 through (halfway done with the main plot) and am enjoying the hell out of it.
The thing that hooked me was the lack of resources. It feels a bit like a survival game on hard, and there are gimmicks within the item system and leveling system that make it very enticing to a completionist.
I keep calling Hope variations of Vahn and Sora, and I'm pretty sure Vanille is some kind of pokemon for the first half of the game, AND admittedly the [spoiler]suicide bit OMG HEAVY ISSUES, 'moms are tough' and Hope's seemingly endless supply of emo[/spoiler] are a bit annoying, but these are only marginal annoyances with the icing.
The delicious cake itself is a battle system with time as almost the only resource. Instead of mana, spells take only a segment of the Active Time Battle gague.
A very basic outline of the battle scheme: All enemies (and your characters to some degree) have a chain gauge. Magic makes the chain gauge go up. The higher the chain gauge, the more damage attacks will do. Physical attacks slow the chain gauge's rapid depletion. Debuffs and other saboteur class moves also do this, as well as further weakening enemies. If you libra an enemy your allies will automatically target it with what it's weak to.
The basic strategy is to determine if an enemy is weaker to physical or chain-gauge defeat, then, by switching between pre-created job class templates during the battle, hit them with that weakness. It's much more complex than that once you add in dozens of other factors like chain-gauge resistant, magic resistant enemies that must be debuffed or Summoned out of your way.
The trick is finding the perfect combination of job classes to unbalance the enemy and cause it to Stagger by filling the chain gauge, at which point attacks nearly double in damage for a time.
There are only maybe 100 equippable items. This means that instead of buying new items, you level up the ones you have already, and eventually evolve them with special components into the next form (most equippables have three forms). Each item can be leveled up with organic and mechanical components which bestow experience on the item. Organic items increase the multiplier applied to the experience each component puts into the item and mechanical components are worth tons of experience but instead lower said multiplier. The trick is to put just enough organics into the item to make the multiplier x3 and then pump in a ton of mechanical components to drive the XP of the item into crazytown. I have a sword right now that is basically owning, though I had to grind about an hour to make it so buff.
Each item 'class' (such as HP increasing gear) can be mixed and matched to synthesize extra abilities. So if I put two or more Boost-type items on, I will always synthesize active time battle increase on that caracter.
I'm currently planning to have Vanille (who has a pretty tragic story, actually) as a healer/saboteur/ravager, Snow as a sentinel/ravager/commando, and Lightning as a ravager/commando/medic. As I level those three sphere-grids for each of those characters I can switch between their jobs in-battle and almost instantly. The only thing I'll lack is a synergist, but I can make up for that later.
Anyway, yeah, don't listen to the haters. Like all FF games, this one is so different that comparisons to others are relatively pointless. This one gets high marks from me.