The better question is if Graces is better than Vesperia.
In all honesty, I feel Vesperia was the best Tales game in terms of overall gameplay, progression, and flawed characters that you were able to like despite they're flaws, unlike Abyss where Luke in particular was just impossible to like until his drastic change. Graces had some problems in terms of characters, in my opinion.
As for Xillia... That is looking quite promising.