If my save file is to be believed, I'm roughly 21 hours into FF13, somewhere in Chapter 9.
There's quite a bit I could complain about in FF13 - and I will - and yet I'm still chugging along. For all the game's quirks, it is paced remarkably well, and I find myself frequently saying "OK, let me just get to the next save point and I'll quit" and then another hour has gone by. And while I'm generally not that inclined to grind all that much, my characters are versatile enough now so that I can make meaningful changes to the paradigm system, and it's quite satisfying to then be able to kick all sorts of monster ass quickly and efficiently.
Still, though, there's a lot to complain about. The first thing is that almost all of the dialog could use a good rewrite. The second thing is that, after the rewrite, the voice acting could use a second pass. (And the person portraying Vanille, and the person who cast her, could both be shot.)
But more to the point - the cutscenes seem very much disconnected from the gameplay; i.e., you'll be strolling along, killing things, and then you'll cross some threshold and your characters will start talking about how they can't fight anymore, or that they've lost hope, or what does it all mean, etc., and perhaps there will be a flashback, and then they'll get momentarily rejuvenated, and then the scene ends, and you continue fighting monsters as if nothing had happened. I don't know if this is something present in all FF games or not, but it feels a bit clunky, especially considering that you (the player) have absolutely no control over how the dialog plays out.
Now, I'm not entirely sure that FF13 would be better if it felt more like Mass Effect 2 - frankly, it might just feel silly. As it is right now, it's merely corny, and occasionally clunky. And sometimes it feels a little too cute.
I guess a bigger issue is that all I'm doing is simply moving from point A to point B, without a particularly clear sense of why. I'm only now starting to understand the underlying fiction; the "l'Cie" / "falCie" business could've been much easier to understand if they'd simply picked different names. (I still maintain that I'd have ABSOLUTELY no idea what anybody was saying if I wasn't playing with subtitles on.) I'd like to feel a bit more invested in what's going on.
And another part of that is that the leveling system is strange. A battle does not reward you with XP; it rewards you with crystals, which you can then use to power up your various paradigm elements. It makes sense, to a certain extent, but you're only able to make significant upgrades after you complete a chapter, which makes grinding feel even more redundant than it already is. (I've really only found myself consciously grinding once or twice, and that was only because enemies were quick to respawn, yielded high amounts of crystals, and were very easy to dispatch.)
Still, though, I find myself compelled to keep carrying on. As some point I hope to be able to articulate why.