Thought I'd come here and give my experience with this problem as well.

A few weeks ago, my video card died on me (ATI Radeon hd 5770). I waited impatiently, running my computer off of my on board video card (ATI Radeon HD 4200 Graphics), of course the thought of even attempting to login to ffxiv was out of the question.

Well, boredom got the better of me, and i gave it a shot. Not only was i capable of getting into the game without changing any settings, it was playable... Performance took a small hit, but if i was outside of a city, just killing mobs, it was completely functional. This made me feel a little better, knowing that it wasn't my machine causing such horrendous lag, but rather the game. As every other recent game that i've played gives me no problems what-so-ever.

I really can't see myself playing again until this problem gets addressed. The loading lag, combined with the UI lag makes what would be an enjoyable game feel clunky and unfun.