I wouldn't say it's better than FFX yet. If it's better than FFX, that means it's better than FFVII and VI for me. It's definitely better than I-V, IX, XI, and XII though. Then again, I have yet to beat the game! But still, those 4 games are classics in my opinion and it'll be hard to top them.
My problem with the game is mostly the story. I like it a lot but right now, where I am, I have no clue why I'm going to this country I'm heading to. I forgot why. With FFX, you always had one goal the entire game: get to Zanarkand, in this, I'm kinda wondering what my goal is. Maybe I just need a fresh reminder.
Another problem I have is the ring system. It's nice, but it'd be even better if it were more fleshed out. I think all skills should have a time based system infused with them. For something like Cut Down, they should have included something like Tidus' limit breaks in FFX, where you have to time something in the middle, and if you make it, you hit all targets. For something like Mack's Combo move, they should have opted for hitting two Rings in a row to determine the damage. I think they should have infused the rings more into the battles like in say, Shadow Hearts, is all.
Also, while I think the Immortal -> Mortal system is great, I think they give WAY too many mages. 4 is too many. All you really need is a black mage, a white mage, and a spirit mage (aka Mack). So that's really just 2 mages. I guess that's apart of the reason why Ming and Sarah are my least favorite characters so far.
There's a lot of kinks they could have done that would propel this game from merely being GREAT to AMAZING. Still though, this is, by a wide margin, the best next gen rpg I've played (an no I haven't played Oblivion yet...well, I have, but not for long).