I have criticisms about the existence of Priest Holy and Discipline Priest.
There is no reason to be two separate talent trees for them, the difference is very small ...
Both have a ridiculous DPS, and serve only to Heal ... One has a few buffs and a better shield, another has a cure a little more AoE, could better distribute between these two options only HOLY talents for example, and turn Priest Dicipline in another more different thing ... or a holy DPS or a tanker cloth (that would be unheard of) ... I do not know what would be the novelty, just do not see the sense in maintaining two trees so alike ...