I agree that we haven't gotten another game that felt as polished as Vesperia did, at least not yet.
As a fan of the Tales of series, I enjoyed Graces f and Xillia, but they definitely lacked a certain "something" that Vesperia had. The cel-shaded style definitely does a lot of good for it, but the story, setting, and main characters also had something about them as well.
I personally felt Xillia 2 was lacking for a number of reasons; to me, the story often felt like a bunch of nonsense, the debt system interrupted the flow of the game, the large number of re-used / unchanged assets from the first game compared to the low number of new ones felt lazy to me, and Ludger being a silent protagonist felt forced and at times worked against the game. My lasting impression was that the game felt unnecessary. It wasn't bad, but I actually preferred the first game.
Unfortunately, Zestiria has little going for it in terms of how it appeals to me. I'm not a big fan of the majority of the character designs, I don't really like the "look" of the game, and I'm not really interested in what little we know of the story / plot. But as a fan, I'll reserve any final judgement until I try it out for myself. I may end up loving it, who knows. The battle system looks pretty good so far, and as much as I dislike vast, empty fields, Zestiria's look like an improvement over Xillia's.
Damn though, sometimes I dream about a Vesperia 2. Ahh...
