If they butchered the battle system and any semblance of classic FF feel, then probably neither. But I'll jus twait and see if they don't screw this up bigger then they did X and VIII.
Since FFI-III had no ATB bar, and X locks you into jobs for a large portion of the game, I would say X was more "classic feel" than most.
Anywho, If I had the money for a Ps3 anyway I would be buying Versus-XIII first.