Holy vs DiscFollow

I went holy and disc on my dual spec also. I had shadow for a bit, but I'm raising my warlock up for dps instead. My preference is disc. I use shields allot in 5 man heroics (I'll generally shield the whole group to mitigate aoe damage). Penance is great for quick heals. Renews can be tossed out quickly to multiple targets, and we still have PoH (which you can now throw on groups other than your own). Of course there is still flash heal and PoM.

The point is that we aren't limited to single target healing as disc. As far as holy goes, I definitely switch to holy on Loatheb. The combo of PoH and CoH during the 3 seconds of healing is awesome.

It's great we have two workable healing specs. Dual spec lets you have both at your disposal. Use the one that works best for you and suits your situation and play style. One isn't better than the other. They are simply different.

Edited, May 29th 2009 6:01pm by dadanox

Holy and Discipline are actually remarkably similar in their capabilities. Neither is better or worse, per se-- they're just different. Holy provides superior area healing-- but Discipline offers Renewed Hope, an area damage prevention measure. Holy boasts superior healing throughput; Discipline is better at preventing spikes.

If you play Discipline, you have to learn to ignore the meters. Meters won't provide an accurate measure of your performance because Divine Aegis and Shield aren't counted. If you want to get more of a sense of what your true healing is like, look at how much your Glyph of Power Word: Shield is healing for. Multiply that times 5; that's how much you're Shielding. This doesn't account for over-Shielding but gives a rough approximation.

Incidentally, if you're not using Glyph of Shield, you're doing it wrong! Glyph of Shield and Glyph of Penance are nigh-mandatory for a Disc priest, since those are your two best spells. In Mimiron, for example, Glyph of Shield accounts for up to 14% of my non-absorbtion healing. I round it out with Glyph of Flash Heal, but for my PvP build I use Glyph of Dispel Magic instead.

To get a sense for Divine Aegis, do this:
Raw healing x (crit chance x .3) = Divine Aegis shields

For a crit chance of 33%, for example, Divine Aegis effectively adds 10% to the applicable healing spells. It does nothing for Shield or Renew, though. The healing from Glyph of Shield isn't "your" healing for the purposes of Divine Aegis.

And, as Mozared alludes to, your gear matters quite a bit. If it's heavy spirit with a mix of crit and haste, it's better for Holy. If it's heavy on the intellect with lots of crit, it's naturally friendly to Disc.