I'm actually about to beat Vesperia (can go to final dungeon anytime now) and I have to say, I love this cast. There's just something about this disparate group of personalities that gels well for me. Really, I like every single one of them, but this is not strange, since I haven't met a Tales party character I haven't liked. There are some I'm neutral about (Colette) but none that I didn't like. Raven is totes my fav character, though I do not like playing as him.
Abyss is still going to be the best Tales game for me (of the 3 I played), but this one is very close in quality. That being said:
Abyss's magic > Vesperia's magic. I just loved that magic in Abyss came essentially from music, while Vesperia's feels like it's being made up as it goes along.