Another ability that I had hard time dropping. Disadvantage of it is, that it is the only shout that is not generating any fury, and actually costs 20 of it. Sometimes you may end up not being able to use this because you will be trying to stay alive by using Seismic Slam. DO NOT drop War Cry in favour of this shout. WC is just too good to pass up with its boost to all of your resistances. If you lack some damage, you may pick up Battle Rage and War Cry at the same time. Unarguably, Marauder’s Rage is the best rune for it. Well, I suppose that Swords to buy Diablo 3 account Ploughshares might be worth looking at, if you decide to pick Pound of Flesh passive and depend on health globes. I would say that Battle Rage complements well with Ruthless passive and Hammer of the Ancients ability. In other words – heavy crit based build (you might need some crit on your gear for that).
This ability might also be good if you need some high DPS along with Diablo 3 items strong burst for certain encounter (for example for Inferno Rakanoth). You could sacrifice your fury spender (for example Seismic Slam) and replace it with this shout. You should get a lot more damage by having BG up, being on max fury with Berserker Rage passive on and by just mashing your Frenzy button.
20% flat damage reduction every 15 seconds is nice, but I done some testing and in my opinion War Cry with Diablo 3 items buy right rune gives you more survival and damage migration in the most O SHIT situations. Tempting thing about Threatening Shout is its rune: Demoralize. You get to actually TAUNT your enemies for 3 second. Yes, you can capture aggro on mobs the same way tanks do in WoW by using this ability.
2000% weapon dmg is HUGE. I find this ability to be working best along with Wrath of the Berserker. Do not pick it up instead of WotB – it is just not worth it. You will do less damage (well maybe not in aoe situations, but it is still not worth it ) and also, you won’t get survival bonuses from WotB. As for runes, pick whatever you like. Chilling Earth gives you very nice CC and The Mountain’s Call works very well with Boon of Bul-Kathos passive.
Some people like to use this, so if you are one of them then by all means... 4 sec long AoE stun is very nice (less effective in inferno, because inferno mobs have default cc reduction time), and 12 sec cd on it is not bad, not bad at all. Try it and see for yourself if you find it useful.