Originally Posted by
harky
Holy Priests only appear to have better burst raid wide healing because when both are in a raid the Holy Priest will typically be overriding HoTs with direct heals. If you switch a Resto Druid for a Holy Priest what you'll find is that unless your raid is organized by fight position the Resto Druid will handle the 'burst' AOE situations better. It's simply a case of Wild Growth and Rejuvenation healing for more than Circle of Healing and Renew.
The reason Disc is encouraged with Resto Druids is because contrary to what you claimed Holy has a negative synergy with Resto Druids. When a Holy Priest is present the Resto Druid will be worse than they would have had the Holy Priest been replaced by another healer. The Holy Priest actually hurts the Resto Druid. The opposite is true of Disc because the way that Disc helps the raid is through shields, which means Resto Druid HoTs assist the shielded target, but the shield remains. That's synergy. Holy Priests have for a very long time been known as a heal sniping class. They look good on meters because they can beat other healers to the punch.
The best way to see it is if you have both. Check the over-healing on the Priest compared to the Resto Druid. If the Holy Priest is doing what they're best at the Resto Druid should have at least twice as much over-healing. If the Holy Priest wants to be a real prick they can even push the Resto Druid into the high 80s on over-heal percentage. Then again Discipline can do the same thing on a fight like Archavon. Reduce all raid damage for the entire fight to about 50-60k and watch everyone else ride their way to 95%+ over-heals.
Synergy is about two classes working together to produce something better than the combined total of their work separately. Holy + Resto the Holy Priest appropriates HoT healing which gives them more healing, while converting the Druid's healing into over-healing. Disc + Resto this does not happen, the Disc Priest protects targets in danger from dying while HoTs do their work. Holy + Resto only has synergy in that Holy is the most likely healer to run into mana problems, so Innervate is nice. Disc + Resto has a true synergism.