In my case, my summons always die before they run out of time. And since I can learn flame/frost/storm/death thrall, I regret that I took conjuration dual casting perk.

I hope that instead of extend the duration, dual casting can summon more powerful monster.

I didn't even realise the point of dual casting, like you said, my familiars usually die before they run out as well.

Dremora Lords can usually hold their own through the duration of their summon. So I have a use for the perk, personally.

For lesser summons that cost less magika? I probably won't put in Dual casting on Conjuration unless I feel like it would help a lot.

the permanent companion is the worst perk i can think of for conjuration. it would be nice to be able to get rid of them without having to kill them before i want to run somewhere because they are so freaking slow or when i want to sneak. the only mildly useful permanent compainon is when you equipe a corpse with really good gear and raise it. you still have the problem though of it being slower and less sneaky though. i would have preferred extra summons like clanfers or my biggest wish of being able to summon a daedric lord for a short period of time once a day.

If you're summoning familiars and raising weak zombies, then you're right dual-casting is pretty pointless. But with the higher level conjurations such as atronachs and dremora, it's almost like having a portable companion. Definitely useful in higher levels.

Because Dremora Lord's are more powerful than the thralls?

where have you been? dual casting is worthless in any school.

Usually there is a lot of time between the point when you can get dual casting and the time you get Thralls.
Also Magicka regenerates much faster when you are out of combat.
So when you have longer lasting pets you can just summon them even when there are no enemys and
start combat with full Magicka.

There is no "permanent companion" perk in Conjuration. The Master-level spells are all permanent to begin with, and the last perk in Conjuration on the left side of the tree IS one additional summon.

Exept for Restoration maybe they are pretty usefull.
And I dont know the spells of high level Restoration so it may even be usefull there.

If that's the prevailing sentiment no wonder people believe Destruction scales poorly.

Dual casting is useful for over half the school's spells. Bound weapons not disappearing in the middle of battle is a plus, soul trap lasts longer, I also use dual-casting when I want to summon or revive something non-permanently, which is a lot of the time, as the thrall spells are very costly and take ages to ready, and also, I see no point in "Thralling" a simple bandit. Then again, generally in the simple bandit situation i'll just single cast.

i was talking about the thralls. you get them from a seperate quest from creepy guy.

It makes your Dremora Lords last longer, and since those are more powerful than pretty much any thrall you can get there will always be a reason to use them.