I can bring in another perspective on this as I'm also a fan of FFX-2.

As a game it is severely lacking. The dialogue is very genki girl. The tone is far too cartoonish especially compared to the previous game. Some of the costumes feel like unnecessary fan service. It can also feel disjointed since most Final Fantasy games are linear while this one was mission-based.

However I think they did that on purpose. The point of the game was for Yuna to live the life of a young woman that she was never supposed to live because of being a summoner living during the Age of Sin. Everything we're seeing in FFX-2 is a brand new era for the world so they're all trying to find their way. The music is a dramatic departure from traditional entries too. And so the story itself is about trying to tie up the loose ends of the past so that they can truly live in the new era. The final boss is from the ruined nation of Zanarkand and even physically looks like the man Yuna had to give up last game.

Anyway the reason I liked it was that it developed the history of the game more than FFX ever did. We learned more about what happened to Zanarkand, the true costs of the war and even how it might tie into FFVII which is what Kitase had revealed in an interview. Basically the Dressphere job class system is a precursor to FFVII's Materia and of course Shinra is an ancestor to the Shinra family that would eventually found the ShinRa Company.