As a priest, I’ve often found the two healing styles to be very separate.  It’s very fun to switch back and forth to feel which one will be best for what fight.  Even more so; this is important for certain 10-man Ulduar hard modes… if you don’t always have a solid composition for these raids, you may be interested to making your dual specialization to be disc/holy.

Here are my comparisons of each spec and what it does well to me.  It may be very different from what EJ or any other source may cite.  This is, though, an opinionated and angry blog about things that I like talking about.  So sorry!~

  • Holy Priesting
    • My priorities when I am Holy are to heal the raid and be tank support if needed.
    • I use Renew as liberally as I would Power Word: Shield because its general effect is much more heightened than when my other spec.
    • I will use Circle of Healing usually when it is up, though I will not if there is no damage being taken often.  I do not use it to snipe from HoTs.
    • I will use PoM when it is up (same as Discipline, though Holy gets some mana efficiency through Healing Prayers).
    • I rely on Flash Heal to have my 3 stacks of Serendipity.  I will observe when I have my Surge of Light proc and use accordingly on a tank.  Generally, I will only use Prayer of Healing when CoH is down OR the damage taken is much higher than a CoH will do the trick for.  Greater Heal is still used as infrequently as possible, but will be used if tanks are getting hammered (e.g. Algalon).
    • I am not afraid to use Guardian Spirit if things look bad, as my glyph will prevent a super long cool down if I don’t predict well.
    • Power Word: Shield is great if you have Body and Soul; also, the ability to essentially have Abolish Poison is fantastic.  However, be wary of Discipline priests if you have one.
    • I will spec Holy if one of the following is true: there is no Druid in the raid; the other healers are better suited healing tanks; Guardian Spirit being more effective than Pain Suppression in certain situations.
  • Discipline Priest
    • My priorities are to heal a tank or multiple tanks.
    • Power Word: Shield is used liberally and as much as possible to maintain the 3% damage reduction (if no Blessing of Sanctuary) and to keep up Weakened Soul (making Renewed Hope effective) for Flash Heal support (on tanks, Penance added).
    • Prayer of Mending is always used when up.
    • Flash Heal is my filler spell, as per usual, only my goal is to crit as much as possible to proc Divine Aegis on tanks.  It is supplemental to non-tanks, but not a priority.
    • Both Greater Heal and Prayer of Healing are both low priorities at all times.  Both are only worth the cast times if a Borrowed Time is present.
    • Renew is a two-fold approach.  It is great on tanks.  It is, for the most part, a waste on raiders in a 25-man situation.  If no Druid support, then it is a good idea if you can afford the mana (and the time spent using Global Cool Downs on other raiders).
    • I will be Discipline if one of the following is true: there are no other Discipline priests in the raid; Paladin not being enough to cover tanks; enough HoT support through Druid + Holy Priests is solid.

It must be stated that this is all moot depending on YOUR OWN healing situation! Our 10-man Ulduar raids are usually comprised of a Holy Paladin, Restoration Shaman, and Holy/Discipline Priest (myself).  Sometimes, we will have a Restoration Druid over the Paladin.  However, know that your roster will also affect your raid buffs (and personally, I prefer BoK over GotW) and debuffs.  You must be able to play your own raid properly to have the most effectiveness.

I must also remind, this is opinionated; my play style might be completely bat-freaking-crazy.  Know that I acknowledge this craziness.  But if it gets results… well, yeah.