I'm not agree about useless of win8. Even win7 applications runs a little faster on 8. And 8 boots much faster then 7.
With FFXIV 1.0 on win8 I got +10 fps. It's not much, but it counts. I don't say that you must setup 8 on your machine, but it's not useless.
You can hate it's new interface, but 8 shows very good performance.