Tarskin has pointed out that I forgot the difference in Maul and Lacerate dots when they get 4% MMS damage. So I did the math again. MMS is better by 1.3%.
Let me state first that this post is a comparison between a very popular tanking spec 0/55/16, holding SS and MSS, and an alternative spec 0/60/11 holding iMangle and no MMS.
I forgot Maul and Lacerate dots in the rotation. The damage for MMS and not MMS is different of course.
So I went back to rawr. Because some values had changed I redid the spreadsheat.
Some weird things I saw; Windfury totem changes the damage per maul. Of course it changes the total damage by Maul, but now also changes the average damage and threat done by Maul apparently. If anyone has an explanation for this I'd like to hear it.
It shows that with WF totem the threat you loose with iMangle rotation is 105 threat per second. This is 1.3% threat loss.
So if you are looking for max threat, MMS spec is the way to go. Well, to be honest, drop something like IW and ask someone else to apply the same debuff. Get iMangle too. That does the most threat.
However you can also ask the few top dpssers to hold back a little bit or use some threat reducing effects (FD) or get hunters and rogues to misdirect to you.
Still, in the end, my conclusion stands I think. 1.3% threat loss on a boss is something not that bad. You get 5% more uptime from Idol of the Corruptor it halves it's downtime. That is worth it I think. If you can dodge an attack that otherwise would have killed you it saves you from a wipe.
PS. This all made me think to what things can you expect normally for being raidbuffed (25 man).
So my next post will hold the raidbuffs you can normally expect in a raid and should be checked while comparing items to eachother.