I also have 4 DK (currently at lvl75) and now need to decide if I should have a priest or pally as healer.
My setup is going blood tanks with all four DK so aoe-healing is nice since all four takes damage. Priest are better aoe-healer (at least at this level) but I truly love pally's holy radiance at lvl83.
If going pally my strategy is to now randomly cast holy shock (using /targetparty in macro) and then cast Light of dawn now and then.
Priest may be better aoe-healer, but I like the idea of having plate classes only since they all can take more damage then.
Opinions please? Which of the two is a better choice?

Connect With Us