I've played all of the Tales Of Games that came out in America (except Radiant Mythology) plus the three Japan-only DS games and I found Vesperia to be among the best. I'm not saying that you're wrong (as I acknowledge that video game enjoyment is very much a personal opinion), but I'll explain my reasoning:

1) Yes, the cast was atypical, but I felt that this was one of the game's strengths. Instead of being about a teenager coming to age or the loss of innocence, the game is about a man who is already sure of his beliefs. The game doesn't focus on Yuri's changes, but how his convictions change others.

2) The story, I felt, was one of its other strengths. Unlike most JRPGs, the driving force was not some overarching need to save the world because the main characters are special. Instead, it is the main characters doing what they believe is right because they believe it. I felt that this gave the characters personalities unlike any other seen in the Tales Series.

3) I'll give you that the dungeon encounters were kind of chunky until you got the ring to the fifth level(which was endgame so it didn't matter). The battle system, however, is a much smoother one than Symphonia due to free run. I also feel like the overlimit system is a step up from Abyss and the Free Run is (understandably) toned down from that.

The biggest downside to Tales of Vesperia, or indeed any Tales Of Game (except for Legendia), is that any given game's soundtrack normally only consists of a dozen or so memorable pieces. However, I believe this to be true for most Tales of Games, so I don't hold it against Vesperia.

It's difficult to compare Tales of Phantasia (which was great for its time, don't get me wrong) with Vesperia. Phantasia has a very "old school" RPG feel. You have your fighter, your healer, and your mage--everyone has a concrete class and personality that's typical of that class. The only true exception to the stereotypes is Dhaos himself. In regards to the story, I believe Phantasia is pretty decent for its time, and the "twist" at the end is one I enjoy.

For your reference, here's my "Tales Of" order of preference: Symphonia, Vesperia, Hearts, Legendia, Dawn of the New World, Eternia, Abyss, Phantasia, Innocence, Destiny, Tempest. I don't believe I missed any, but it is possible I have.

Once again, I don't mean to offend or argue, simply to offer an alternate point of view. I know there are a variety of opinions on Best Tales Of game, as well as worst.