Set your spirit to the one end of the hall, and when you are coming down dodging tornadoes, you can skip the last 40 yards by just getting behind the boss. This is even more valuable for a healer to get down there and stack SCK/Chi Burst spam.
For Feng, you can set your spirit in the middle and get there faster to get out of Epicenters quick in case you can't get a stun off.
For Sha of Fear, you can set your spirit inside of the safe zone and use it to instant teleport you in there before Sha uses his breath thing.
For Elegon, you can set your spirit on the outside to get off the platform for either clearing stacks or before the floor drops out for extra DPS on the boss. This is especially good if you are pushing enrage on the fight. --- http://us.battle.net/wow/en/character/black-dragonflight/Arpandaday/advanced http://i.imgur.com/SpVUU.jpg