After looking at the DPS data for all my group members in Recount I calculated that my combined DPS from all group members for my Retribution Aura was averaging around 60 DPS, which to me seems pretty minuscule and in any normal situation doesn't seem like it's matters all that much.
My Devotion Aura adds 1205 Armor to the tank and Resistance Auras add 130 resistances, to me it seems like in the close situations those could be the difference between wiping or not, more than the slightly added DPS would anyway.
Wouldn't it be better if I just used those instead and saved my Retribution Aura as an unfair Honor Point hording system in BG's?
if your retribution aura deals 160 damge on hit, that is then about 380 threat "for free" for a paladin with RF active, for 2 sec swing timer this cna be as much as 190 tps. while not much, it IS stil damage done to the boss. if a boss hts you 100x per boss fight (assuming 50% avoidance) that is 100x160 = 16000 damage over the fight.
auras are useful if you have incoming magic damage of that school, but at a boss like saurfang there is no magic damage. typically you have multiple paladins in the raid, plus prayer of shadow protection, and almost never more than 2 magic schools in a fight.
tank: devo aura
dps: aura as applicable, retri aura as free damage
Applicable resistance aura > devotion aura > ret aura