Holy Molly. I just summoned Durnehviir to battle the Foresworn at Karthspire Camp and he in turn summoned an entire army! He had a Wrathman, a Boneman, and a Mistman all fighting along with him. I didn't know anybody could have more than 2 summons at the same time. Based on this, and on his drain vitality shout, I would say Durnehviir is more potent than Ohdahving.

I absolutely love Durnehviir. I'm just sad that he banishes all other summons on the field.

So far I've just summoned him for the Soul Tear shout. I didn't even know he could summon his own minions...

odahving+Durnehviir would be interesting, one is a summon and the other isn't, if only their shouts recharged faster

You know what svcks Storm Call, seriously used it against a dragon and it in turn killed all the guards trying to kill the dragon and now I cant go back into Falkreath

I should have used Durnehivir instead!

Well that's a learning experience for you. I never use large area-of-effect magic near towns (unless it's Harmony).
I have not seen Durnehivir summon anything yet. I will have to use him more.

Well, he is forever bound to a gloomy world of pure misery for eternity, only ever leaving to be summoned by the Dragonborn for combat, and who knows how long that's going to last. He could be killed by anything at any second, and Ol' Durnheviir going to have to wait for the next (still alive) Dragonborn to go into the Soul Cairn and best him in combat!

But other then that, yeah, he did get a lot of neat necromancy powers.

It's possible if you use the restoration potion to make shout cool down %100.

In most cases when I summon the big flying corpse he kills what needs to die then flys around for A WHILE, in msot cases he goes around for hours, if I wait he goes away but if I just stand and watch him in real time he can hang around for up to 3-4 hrs, at least for me he does.

Fortify Restoration glitch plus talos amulet. Super fun. Should be tried at least once.

Does Durnehviir have eyes? Because I can't find them on its face. Oh, and it's epic. Loved the Soul Cairn. Gave me memorable goosebumps.

It is pretty cool.

In Winterhold, I was fighting a Frost Dragon and decided to summon Odahving and Durnehviir, only to discover that a Legendary Dragon just landed as well.
4 dragons, all flying around looks pretty damn cool.