So I checked FF X and the PDF is 163 pages of actual text etc.
FF XI will be about 190 pages.
Except that 48 pages of FF X was a rewrite of the game rules for dragon player characters which was necessary but went very quickly since all of the basic material was already written - FF XI is all new material. So in terms of new material, FF XI will be approaching twice the size.
No wonder it seems to be taking a long time...