Could anyone in Legion visit Pandaria and look at the same spot, check the fps and then do the same on the current live servers - both with addons disabled? I would like to know if the engine in itself is now faster or slower. I know that Legion added extra details, so it needs more performance in general. I just would like to know if they managed to optimizes the engine or if the engine just added new features and is now slower in general.
About the 30 fps vs. 60 fps - to all who think there is no visible difference. Just check this yourself.
http://www.testufo.com/#test=framerates
You see no difference? I can even tell a clear difference between 60 and 120 fps (my monitor runs at 120 Hz).
Here a comparison in WoW:
Check the edges of object when the camera turns...