Pld is the worst main tank but remains a meta tank for it's utility, AKA Cover, Veil, plus 2nd for overall tank DPS and it's cooldowns are very open to any raid/ex trial. - Pld for simple game plan it's the easiest to play.

Drk is the best main tank with Warrior, however it isn't a meta tank and it's horrible for certain current Savage raids. - Fun cheesing mechanics with TBN.

War has a lot of self healing and Holmgang which makes it a solid main tank, but it's DPS falls too behind the other 3 tanks. It's a rocket that burns fuel quickly DPS wise. - Fell Cleaves for big number damage.

Gnb requires a straight up un-interrupted GCD burst window or it loses a pack of DPS, however it's the meta main tank and currently does the best DPS out of all tanks. - Solid animation and a lot of cooldowns.