A couple thousand hours of play sums up to camping the same repetive enemies, dealing with gil-farmers, and subbing NIN.
FFXI Cons - Slow installation process, terrible economy, many jobs end up equipping identical "elite" gear, very dry end-game, boring and tedious experience grinding on repetitive monsters, quests are so uninformative you resort to online guides at all times, job classes are unbalanced, some jobs are completely worthless, and the crafting system is the worst in the history of MMORPGs.
I was once a great FFXI player. My first job to 75 was my Dark Knight, which was lackluster when compared to the pre-patch Rangers and their game-breaking damage. I then took a few other jobs to 60 and became bored with killing crabs, beetles, and crawler worms. After a long break, I came back to the game and leveled NIN to 75 and finished most of the end-game material in a few months. Just when I realized that the game was nothing more than taking a job class with a pitifully small number of skills to level 75, I decided that it was time to quit.
The millions of gil that I made didn't mean much at the time because of the rampant gil-farming problem that plagued every server. After looking back at how much money that I had spent over the years just to play the game, I figured that I should at least try and sell my account. Anyway, that is ancient history to me, and the game is done.
If you are looking for a good MMORPG try World of Warcraft.