I really enjoyed my time on FFXI, but I had plenty of problems too. Probably the biggest ones was there really was not much happening in the areas themselves. I mean a lot of zones were devoid of NPCs or anything like that. You had very little reason to travel anywhere other than to hit a leveling area.
It's not even just a simple matter of scattering more npcs in places. It would be nice if they were involved in quests or something story related so you're kind of exploring with a purpose. Maybe there could be a small group of NPCs that got injured by a group of goblins or something and they need you to help. Something small like that which makes the world seem more dynamic.