Elemental damage vs choosing another skill

[Fhi]

Another question for you experts!

There are builds that utilize one specific type of elemental damage and then stack +elemental damage on gear. Not sure how to explain what I want to ask, so I'll just use an example. Let's say I go with lightning on a demon hunter. I want to put Fan of Knives in there somewhere. There is a lightning-based Fan of Knives, that stuns. Suppose I don't have any stun-related legendaries, so it's just a nice CC in addition to regular damage.

It does 450% weapon damage. There is a Physical rune that does 1200% in exchange for an additional 50% cooldown increase. Would that rune be superior to lightning, even if I have +60% damage to lightning attacks, since 1200% is almost 3x 450?

[Flashforcash]

some simple math if what you say is true then: (its prolly not totally accurate the way i did it, but lightning should still be superior)

450 * 1,6 = 750% damage

1200 * 0,5 = 600% damage

so yes lightning rune would in the long run turn into more dps, but obs if you want shorter burst the psy would still be better.

[Belmorn]

More like 1200 * 0,66 since he the CD is increased by 50%, every 3 normal casts he only gets off 2.
so 1200 * 0,66 = 792% damage
Id personally go for the lightning still as I prefer shorter CDs on stuff so you can open with it ( if its aoe ) on every pack you meet

[Fhi]

Ah, I didn't take that into account. Are CDRs only good if you can or have reason to use it right on cooldown always? I feel like if you pick a 100s Archon vs a 120s Archon, if you delay more than 20s when Archon is up, then there isn't a point to take a reduced CD rune.

[Flashforcash]

whole point with doing that is to make sure you can have it up every pack / you play a reduce cooldown build where you can have archon up 90-100% of times (but thats normally with vyrs 4 set bonus that auto give 20 sec reduce)

[S7orm]

it's 1080 (450% * 1.6 elemental coefficient * 1.5 because the cooldown is 1/3 shorter) with a stun vs 1200

but the first have a knockback also, which for me is a pretty stupid thing to put in a spell that already stuns

but for the tiny dps difference i'd go with the stunning option