WotLK imp. Righteous fury for holy

[dolcokidol]

Finally gave in and decided to ditch sub ret spec for sub prot cause DS is just too good in HCs to pass up.
By default, I picked up imp. rf there too, -6% seems nice, now I'm wondering if tanks will be pissed cause I want my 6% reduction?
RDF Tanks seem to have issues, not like I need the reduction there, some lazy tanks let me get agro even on BPC somehow.

The question(s) is/are: does anyone have exact numbers on how is healing threat applied? 0.5 * ammount healer(not overhealing) ?
Does it mean that even JoL will cause threat? Should I just skip -6% since it sounds ok only on HC BQL, Sindra p2, LK chamber and maybe fester?

[Lynea]

The threat multiplier works in the same fashion it does for holy damage. It only applies to holy-based healing threat that is attributed to you. JoL does not generate threat for you, so you don't have to worry about the threat increase there. You can take the talent and simply turn off Righteous Fury when you don't need it. If tanks having initial threat is a problem, simply wait 20s to use Righteous Fury. It doesn't cost mana, after all.

[DarkenedHue]

Should I just skip -6% since it sounds ok only on HC BQL, Sindra p2, LK chamber and maybe fester?

Aren't these what matter the most? 6% less damage taken from every source is a very powerful passive effect to have for heroic raiding, as you rightly pointed out yourself. Just grab the talent and toggle RF off and on as you need it.

Healing threat works like so: (Effective Healing amount x 0.5)/(number of mobs the target you healed is in combat with) = the amount of threat you establish on each of those mobs.

So if you healed me for 1000hp and all of that was effective healing, and I was tanking only 1 mob, you'd build 500 threat on that mob, and if I had been tanking 5, you'd instead build only 100 on each of those 5. The thing with a larger amount of mobs - and this is really the only part where it gets sticky - is that while you do build less threat on each mob individually, every additional mob is an extra target your tank has to build initial aggro on to guarantee that those mobs don't make a beeline for you right away.

In addition to that 0.5 threat modifier, healing from a Paladin is meant to have an extra 0.5x inherent threat modifier on top of that, so the threat modifier in the equation really should be 0.25 if you're a Hpally, although I don't believe the extra 0.5x part that's specific to a Hpally is working atm. Turning RF on then multiplies your threat output by 2.57 or so. Even with inherent hpally threat reduction not working this shouldn't be too much of an issue except on fights with very frequent add spawns where things might start to get troublesome if your tanks don't establish initial aggro quick enough. If you went into ICC with competent tanks and threat redirecters you could have RF up all the way from the first trash pull to LK's death without aggro ever presenting an issue, with the obvious exception of VDW. With that in mind, I'd venture to say the primary factor that regulates your RF being on or off for a given fight, other than details unique to the fight such as adds spawning and such, should be how well your raid members handle threat.