Wow, haven't posted for a long time... Even longer than since I last played (damned university!), so I apologize in advance if I'm tad out of date and miss something fundemental (last played at 2.4 I think).
Quor wrote:
as for when i use it, for tanking its usually on a maul, since it negates the cost of the maul, which if it crits is a net gain of 5 rage instead of a loss of 20+ in most cases.
I have to disagree on it (did I mention that I was feral like... a year ago?! :) ). The way I see it, if you want to maximize the use of your OoC you should use the ability that costs most rage, therefore it should be Mangle->Swipe->Lacerate->Maul, unless one of them is out of the rotation for some reason (no need for Swipe, or Mangle is on CD or whatever I may be missing).
Now why do I put Maul last on the cost list, it's usually considered the most expensive?
The difference comes from the nature of the talent Omen of Clarity, let me clarify:
It's quite clear that by using OoC on Mangle you save 15 rage, same for Swipe, and for Lacerate it's 13 (if talented), while Maul is usually considered to cost 10 rage + whatever you should have gotten from your next attack, but if I recall correctly, OoCing Maul does not make you gain rage on the attack as per usual with "white" attacks (if I'm wrong here please correct me, it's the most important thing I assumed). So in effect, you only save 10 rage by OoCing Maul, the active cost of the ability itself only.
Being practical though, OoC does not proc often enough for you to really care on what you use.
From what I remember from tanking (5 mans only) my attention was usually on the fight itself and the placement of mobs at any given time and not on min/maxing my rage useage, I gave minimal thinking time to my rotation and changing it to gain a little more rage from something very random which could easily cause me to miss out on more important things, therefore I usually didn't change my rotation while at it. Espacially when the rotation favours the skill roughly according to their cost, or at least that what I remember it to be.
Even though I stated my personnal view above, I'd like to show something to support a different opinion,
That's because I might be dead wrong and would like some extra opinions on it, here goes:
Let's assume OoC procs exactly twice per minute, that's according to Wowwiki:
Option 1 - In a 1 minute fight you use both procs on Maul and "gain" 20 rage.
Option 2 - In a 1 minute fight you the procs on either Mangle or Swipe and "gain" 30 rage.
As you can see, option 2 "gains" 50% more from OoC than option 1 (both are extremes, I know), making the talent OoC 50% more effective with the useage shown in Option 2 compared to Option 1. Might be of value on simpler fights.
In conclusion, I don't think you should pay too much attention to procs of OoC (at least for bear form), espacially in fights you are not 100% confident in (a fight you hardly tanked in before, a bad party, whatever), and even moreso when remembering that the rotation favours high costing skills over the cheaper (when thinking how much OoC can save you, maul is still your most expensive skill if you count in the loss of rage from the converted "white" attack).
Have a nice day, and hope I helped somehow,
Yuval.