So I'm like 23 hours in and I take back what I said about the game not being dark. Yuri's plotline is pretty dark for anything Japanese. Definitely moreso than any other Tales story so far.
I think as long as they don't mess up the 2nd half of the game, there's a very good chance Vesperia could have the best Tales story yet. The writers are doing a good job though there is a little Tales filler here and there in terms of "let's go to B, but on the way we run into situation C and have to deal with that, and then situation D, and then we finally get to go to B" that seems to plague Symphonia/Abyss.
Oh and the battle system is flat out awesome. Man, once you get the skill modifiers and the arial attacks (which make it like Destiny-R) and combine them with everything else, the battles are really nuts. It's interesting how they spread out the systems across your characters at first so it makes it interesting playing the other characters. Like for instance Judith is the first to get Arial skill which allows tokugi & ougi air-version. Plus she gets double jump and 4 hit air strings and other air skills along with that. So when you switch to her you're doing all this crazy stuff in the air and then when you switch to Karol you're doing weird charge up moves and wind modified versions of attacks and then with Yuri you're doing other stuff. As you go along the skills begin to mix over so by endgame I'm sure everyone can be doing air combos, elemental tokugis, charge attacks, etc...
Great game. If I had to nitpick anything it'd be that the music is totally unremarkable (which is normal for Tales). Abyss was a little better than an average Tales score, but Vesperia really isn't.