This was actually a rather tough one to decide.

I like that you can automate FF12's combat and the fact you can speed things up in TZA, but it's still using parts of that abonimable ATB system.

Ar nosurge uses a fairly simple combat system, but one I really liked in Ar Tonelico 2, where you have varying attacks on your turn depending on which button you press (similar to xenogears) and you can time your defenses to reduce damage during enemy turns.

Both have their ups and downs IMO which makes them about equal to me. That said, gameplay is more than just combat. FF12 has much better exploration than Ar nosurge, hands down. I like exploration. FF12 wins.