Oh, so you're referring to PLD vs DRK vs WAR, not actually maximizing DPSing as a tank. Gotcha, my mistake, misinterpreted your initial post.

Uh.

Yep. PLD has cleared up to A3S, so all tanks are viable. Didn't know people were actually pretending like PLD's DPS is somehow a crux, weapons are out now and nothing outside of potentially A4S is going to hinder PLD. There's a lot of factors in play as well, there are many PLDs out there who can out-DPS a large chunk of DRKs/WARs. It really comes down to player skill more than anything and how comfortable you are on that particular job. Min/max DPS is really only for world first raiders, things will eventually even out for everyone as there's no mechanic currently that renders any of the tanks completely unusable.