The characters in Vesperia are a whole other level compared to them in Symphonia. That's what really sets that game apart.
I enjoy some of the battle systems in these games, but that's still not while I play them. Xillia has the best of the series in my opinion, but I'm still just playing it for the story, the characters, those hilarious little skits. Man I love the skits. More games should have them. Such a shame they weren't voiced in Symphonia, especially as they were voiced in the Japanese release.