It's debatable, but here's my view on why I don't put more points into it.  As it stands, heals build threat at half the rate of damage.  Thus, a Greater heal that hit's for 5k on average, even if I'm spamming it is only 1k TPS (but 2k HPS).  Meanwhile, a DPSer doing 1k DPS will generate the same amount of threat.  Now, of course, if I'm able to consistently throw out 2k HPS it's because we're in some pretty serious content, where there's going to be DPSers putting out a LOT more DPS thank 1k.  Hell, I seldom need to put out that much even in burst damage situations and our top DPSers hit between 1.2k - 1.6k DPS, depending on the fight.  IOW, I will almost always generate less threat on a mob than the top DPSer, which means as long as the tank can hold aggro against him, I'm safe.

Now, that's not to say I don't pull aggro, I pull aggro all the time, but it's usually when a mob isn't tanked or CCed when it is suppose to be, CC breaks early, or I have an unfortunate timing on a heal after a threat wipe.  In any of these situations, since no on is hitting it, these mobs will always go after a healer because we're the only ones on their threat table.  Hence, reducing my threat will only effect where I lie in the line of healers that will get killed before it gets contained.

Further, none of this tanks into consideration that I still have 1 point (for 4% less threat) and subtlety on my cloak (for another 2% less), and almost always have Salvation in any raid situation (for 30% less), so I'm really generating threat at 32.9% of my HPS.  So, even if our tank can only generate 1k TPS (which is very low, IMO), I ought to be able to throw more than 3k HPS before I'll pull aggro.  Maxing out that talent will only reduce my threat generation to 27.4%.  But seriously, if you can consistently put out 3k HPS... you have AWESOME gear, and your tank sure as hell better be putting out more than 1k TPS if your gear is that good.  Also, don't forget that to actually pull aggro you must have 110% of the tanks threat in melee range or 130% outside melee range, so your threat generation is actually even more flexible than that.

The only point where you do run a risk of pulling aggro is at the beginning of a fight.  This is a point where a missed shield slam or a messed up misdirect could mean a heal will pull the boss right down on you.  This is where utilizing your threat talents is crucial.  As a Priest, you can throw a PW:S on him before the fight starts so it generates no threat, and a PoM.  That's about 4k of healing mitigated right from the get go, 2k of which actually gives the tank threat on par with a Shield Slam.  If you combine that with an Earth Shield from a Resto Shaman, a misdirect, and a Shield Slam, he should be able to build at least 10k Threat before you have to land a heal.  Plus, in particularly sensitive situations, where he needs immediate healing, you can always use fade as preemptive threat reduction to delay when the threat hits so he has more time to generate it.  In theory, you should be able to get off about 10-14k of healing in the first 5s of a fight with negative immediate threat and minimal long-term threat.

This is where PW:Shield comes in.  Some people say you should never throw shield on a tank because tanks generate rage, and therefore threat, from taking damage.  This much is true, but it's only part of the equation.  DPSers can hold off as long as they need to to let the tank build initial threat, but healers MUST heal when it's needed, so anything that can be done to delay healing, particularly early in the fight when it's most dangerous for healers, is crucial.  Considering that most raid bosses will break through the shield in one hit anyway, that he'll be getting PoM threat, Misdirect, Shield Slam, and all that other stuff, the threat lost from 2k damage mitigated by a shield is minimal, but it saves the better part of half of a Greater Heal or more than a Flash of Light, thus allowing either to delay when it hits by as much as a second or two.

Even moreso, to reference back to when healers do pull threat, priests are on of the better classes to pull healing aggro because we can always use Fade.  If we're standing outside melee range (which we almost always should be), we should have plenty of time to let a GCD tick and use fade before the mob gets in melee range and makes it difficult for the tank to pull it back off (where we'd have 130% of his threat, and he'd still need to get 110% of our threat to pull it back off).

So, in summary, the help of Silent Resolve is minimal to negligible in raid situations.  OTOH, PW:Shield, which I don't even use a whole lot, is probably slightly more useful in raid situations, and very useful if you ever to any soloing.  I've found that I pull aggro a lot less often when our tanks/CCers are paying closer attention, I'm appropriately useing PoM/PW:S, and I watch my positioning.  Also, of course, it didn't help that I was completely dominating the healing meters (doing anywhere from 10-30% more healing than the #2 healer), so I tutored some of them and actually passed on gear so they could catch up some.


Both of my builds, either IDS or CoH are ideal for a priest healing a MT.  Obviously, CoH allows more versatility for raid healing, so a CoH priest, while actually slightly better suited for MT healing (from having more points in Empowered Healing), is probably best for raid healing.


Anyway, hope that's helpful and that I didn't ramble too much.