Elemental Maelstrom Mage DOT
 

Says does 250 then another 350 in dots. It costs about same mana as the 44 DD shock of swords and does same dmg of 600 total. So question is what is a good use for it? mabe cast it as your pet engages and you won't get aggro from mob since dot slower dmg on mob? Is this a mob pull spell?

There's not really any aggro difference. DOT aggro is front loaded on cast.

Mob pull spell would be lvl 8 nuke flame bolt. Very low Argo and like 300 range. I never ever use the mage dots. U don’t need to either.

I could have sworn that DoT spells even with a 0 resist modifier had an easier time landing on a target in comparison to a Direct damage spell with the same 0 modifier, due to DoT spells and their basic resist mechanics.
I recall on old retail that I would use Elemental Maelstrom in dungeons with close confines where aggro was a problem due to reduced distance to fight, my pet holding threat, etc. The Hole comes to mind when I was solo'ing the entrance elemental golems (could be single pulled pre Luclin) and using a DD early in the fight was bad news.

Agro difference is in there with a dot.

If you use the dmg to pull and a tick lands before your pets initial attack, the mob will continue to come at you.

I don't think this is true. As a necro I can drop splurt, an 1800 damage dot, right when a mob is first engaged and it doesn't pull any aggro at all.

Aggro starts to build as the ticks hit in my experience.

Aggros are front loaded on anything in game. Ask any warrior with a dot proc weapon.

I've found this largely to be true, with a small proviso. If I toss out either Splurt or one of the Heat Blood or Leech line of DoT's, the initial aggro is very small even if it is a high level spell vs an appropriate level target. The reason for this is is that a Darkness line of spell has a snare component (extra threat), and the poison and disease line of DoT's that we share with Shaman have an initial Damage strike hit of decent value to go with the DoT (extra threat, plus poison / disease counters).

As a Necromancer I can lead off with a Heat Blood, Leech, and then Darkness and it's only by the 2nd spell that it might be tempted to come off of my pet. If I were to lead with the Darkness or make it my 2nd spell on the cast, the mob cares a lot more and will want to pull away towards me.

The total damage of the DoT being used for initial threat is complete hogwash. If that were the case, I could cast a Leech or Heat Blood on a mob and have it NEVER come off of me if I used a pet with its Taunt turned off. We all know that isn't the case, however.

No, the dot doesn’t give you all that aggro. Its the poison/disease counters. Infestation proc only does ~100 damage total. Dot classes will tell you aggro goes up w each tick

Game mechanics disagree but w/e