They can be used, they're a good source of -emnity at low levels while offering both MND AND INT. Basically, they spell win for level 25 until AF (or at least they did for BLM and WHM). I had a pretty good drop rate without any TH last I did it for some friends.. we were I think 2/3 attempts and the monster is a piece of cake if you're a higher level. Just buy a stack of the 3 kinds of mushrooms for you and everyone you know.
Belkira, Tarutaru / Gilgamesh server / 75 BLM, DRK, RDM
Akerius, Tarutaru / Asura server / 99 THF, 99 WAR, 99 MNK
Belmakor, Blood Elf / Maiev server / 85 Prot.PVE, HolyPVP
Belkira, Blood Elf / http://trenchescomic.com/Maiev
server / 85 Subtlety PVP/lolPVE too