Ifrit's eruptions (Japan-based servers = that AOE latency issue affecting most NA players), market wards with no search or category functions (not even in the names), getting lost NOT because the world was vast and unfamiliar but because it was like running around those halls of doorways from the Matrix movie (only "prettier"), 10+ minutes just to clear out junk loot from inventory, double-confirmations required for all actions, rooting around for a 3rd part direct-download option for the latest patch, 90% of the player population being in Ul'dah because it's the middle city in a world far too large for the server population to spread out and still find people to do things with, which was mainly just a handful of dungeons, a limited number of leves, or grinding the same world mobs over and over again with next to no interesting story in between on the way to level cap.

I might miss the old game's graphic engine, a few parts of the world, and the music, but there's no way I'd go back to actually/seriously playing 1.x again, not with 2.0+ here.