I loved XII's battle system because I just really liked the gambit system. I had fun constantly fiddling with the gambits, sometimes trying to come up with the "perfect gambit" that could handle any situation, and sometimes trying to make them as lean as possible.
It was very different from the previous FF's, but I don't think it was gimmicky at all. The gambit system perfectly accomplished the goal of being able to have total control over your characters without having to actually constantly control them. (This is in contrast to XIII's paradigm system, which feels like an arbitrary framework slapped onto the battle system, that doesn't even allow you decent control over two of your characters.)
Also, the lack of transitions into battles, being able to move and run away and be chased, and the fact that battles felt fast and fun! Everything was completely customizable, and you could change anything even in the midst of battle.
And to the original poster, the game must have been a pain in the butt if you only used those gambits! No wonder you didn't like it that much.