Can someone please explain to me why people say attack speed is poor for channeling builds? Yes, I know it drains resource faster but wouldn't that also mean that the damage ticks come faster (which makes dps higher) as well? Or is my understanding of the mechanics incorrect?
It is a complex issue that gets trivialized by both the supporters and the attackers of IAS.
The facts (I hope I got these right)
a. If you cast a meteor that deals 400% weapon damage, your sheet dps does not mean shit on the damage. It looks at your weapon damage (modified by your damage stats) and calculates the hit from that. So for Meteors, spells with high AP cost, spells with cooldown, if you have a slower weapon in your hand, you will see bigger numbers because that is the nature the game. IAS has absolutely no effect in this calculation - your numbers will be the same if you use weapon A with 0% IAS and weapon A with 150% IAS.
b. Channeled spells indeed get faster ticks (I am not sure if this is always the case), but ticks are considered channeling, so the faster the channeling speed, the faster your resources are drained. The only way to counteract this if you have insane resource generation.
So IAS is useful for signature spells (and consequently, if you use prodigy, more signatures spells cast over time means more arcane power regained, which means more meteor summons per minute, for example), and it is useful when your build is not resource constrained in any way. Or when you do not rely on huge cooldown skills or skills that give no crap about your IAS - like explosive blasts, hydras, cooldown meteors, etc.
So yes: IAS when using with channeled spells helps you deliver faster ticks (but lesser ticks as opposed to focusing on CD/CRIT/raw damage), in exchange of faster resource drain. Question is: can you sustain it, or do you even want to sustain it?
