It was just a bad version of the Sphere Grid IMO.
I'll quote that.
I'll say there was no strategy whatsoever in FFXII. It was just hack and slash/heal/bubble. In FFX you couldn't waste a turn because it could become a Game Over.
As for the story, I think the most part of you guys agree with me when I say FFXII storyline sucked compared to FFX. I mean, Tidus was that kind of annoying guy but at least he had a friggin reason to go on the journey! Not like Vaan that I never understood why he went.
Well my vast text resumes to this: FFX is better.