What is the difference? For example, Thorn Totem has On Astral Wind node reducing Projectile Speed and Ancient Power node reducing Cast speed. So what is the difference between the two?
Could be wrong but from what I have witnessed:
- Projectile speed: how fast the projectile moves across the screen. Independent from cast.
- Cast speed: how quickly your character can fire off the spell, which then travels at the projectile speed.
What Kulras has said, but with one addendum, Projectile speed also increases the distance the project can travel I believe.