Easy, ask 2 questions:

Does your group have a BRD? Can the BRD and PLD do the silence duty of ADS on their own? I change to PLD for ADS so we do the silence rotation for example
Does your group plan on doing TwinTania on the future? If your other tank is a PLD, you really want a WAR. Both because they complement so well, and because the LB penalty can screw up a run if Meteor isn't ready for snakes (Building LB at start everytime is booooooring). I for example leveled and geared my WAR exclusively to help my group with TT.

If you said yes to both questions, go WAR, if not, its safe to go PLD.