Being a Paladin, I would say I DECENTLY know what I'm talking about.

Holy paladins almost never go oom.
Ret paladins are constantly packing Pots and Drinks.



So in contrast, sure Holy paladins can only do 2k damage per 6 seconds, but it never stops. Retadins, on the other hand, lose a decent amount of mana after One special move (As seen in the second episode, on the finishing move on the tauren).
The major reason why retadins do almost no Raid DPS, is because all of their spells are almost always on cooldowns, they have 30 second + cooldowns, and only about 5-6 major spells to work with. You will almost always find a retadin Meleeing after about 40 seconds of fight. Holy paladin's DPS is consistent, whereas a retadin does an explosive amount of damage, but runs out very quickly, and even quicker when they have to throw down even one little heal.

Holy paladins can be relied on to do 2k damage every 5-10 seconds so long as they have 1500+ Spell Power or a truckload of buffs.

Retadins will powerhouse until they do about 25k on the recount meter, then will almost always melee the rest of the fight, laying down a judgement when needed.

Retadins server as no DPS, but just a constant pain to keep alive when you see them simply melee in range and taking damage.

Holy Paladins are more versatile and can be depended on. Retadins Drop bombs until their arms get sore, then can't even lift one.