In length I believe that it all depends on what you are doing, Completing or Beating.

To reach the end of the game and be done with it. In this I would think that its not any longer than any other FF game out there...but that would also be cruel and you would miss out on may of the great things that the game has to offer.(Example: Mark Hunting)

To complete the game at 100%.

Now this is a very tedious and long process...I only say this because I still have not completed this game, it has many weapons and armor that I must acquire, it has many monsters to kill...its just an overall long game.

In the end it all depends on what type of gamer you are.