I finished the game yesterday. Took me 103 hours, although I haven't completed everything that was available to me. I was doing side content, and then felt like doing some story bits. Got caught up into the story and had to see it through. I am now doing post game content, as well as completing the stuff I hadn't completed prior to finishing the story. And I think there's plenty of hours left for me it this game.
Now, the game may not beat FF VI for me, in its current state (Tabata said they'll keep improving it with new features, tweaks, and entirely new story elements [!!!]), but I can say that it is the most fun a FF game has been in ages. The story is actually better than I thought it would be, but there's a lot of piecing things together involved. The ending definitely is the best in the series. Very emotional one at that.
For me, it's a solid 90. There are a few annoyances, but the good easily outweigh them. Basically, the camera is annoying when there's lots of environmental assets around, like trees, and for the love of God, they need to fix the 'effin jumping when you get a "press X" action prompt!
In any case, I really like the game, and I can't wait to see how it will flourish from here, with updates and DLCs.
Mild SPOILER alert:
http://i66.tinypic.com/27x2ulk.jpg