I dislike the lack of transition to "battle screen" mode, with the menus and good combat systems of older, better FF games.
I don't see a reason why the spot in the dungeon can't be used as a combat arena instead of spending forever to load the battlefield, the enemies, the battle models, then showing some camera sweeps that introduce the enemies, etc before you can fight. That's my biggest grief with random encounters and zoomed battles, usually the battle introduction and ending takes longer than the battle itself, especially against weak enemies.
I dislike the lack of a Fanfare music, and the lack of victory poses and a screen telling me what I got out of the battle.
That's nice to see if you fight at most ten battles per dungeon but as the number approaches the triple digits that victory pose is just annoying.
I'm not saying FF12 is good but I'm saying that Fallout had a much better combat system than the FFs without any annoying intro and outro for battles, the game just went into turn based mode when you encountered an enemy and that's it.