I would guess that FFXII's world is already bigger than, oblivion or fallout. (maybe wrong)
It was a more flat and barren though. Which made the scenery and landscape look more boring, and the fact that they could hit you from a mile a way if they were locked on.
As for a sandbox environment I'd prefer not... final fantasy's always been linear (Though to what extent always changes). And anyways... there's FFXI and FFXIV for non-linear.







