Tales of Vesperia's strengths come in the form of its stunning presentation and graphical style, micromanagement, real-time battle system (and skill system) and its progressive nature. There's a fair amount of Japanese kookiness though, so be weary if you're not all that chuffed by Japanese humour and story-telling. It's also a massive game with a huge game-world that does, unfortunately, push you on a somewhat linear story path (meaning exploration isn't really encouraged despite the amount of free-roam room you have on the world map). So if you're more of an exploration junky, you might end up being frustrated at the game driving you to follow story arcs instead of the adventurer inside you, but if you're a fan of intricate story-telling, you're not going to be disappointed.
As far as JRPGs go, this is by far one of the best out there. This series has really etched out a formula that works, with welcome incremental additions that only expand the core foundation and experience, and it's safe to say, as it stands, Tales of Vesperia is so far the best in the Tales lineage (at least until the sequel to Tales of Symphonia lands to contest that crown).