A DPS Simulator 2 - SimFF

[Arkenne]

I can confirm you that Spell Speed affects both the Casting time of spells and the Cooldown of the same, hence its twice as useful as Skill Speed actually.

If a spell takes 2.5 seconds to cast and has 2.5 seconds cooldown, with enough Spell Speed you can reduce this to 2.4 seconds on both cast time and cooldown.

This is specially notorious on spells that takes more than 2.5 seconds to cast but still have a 2.5 seconds cooldown, like Fire III or Flare. (Specially if you use them after a proc or Swiftcast).

Side obvious obligatory note: it doesnt affect the OGCDs, of course.

Edit: its also notorious when you use Fire 3 while on Umbral Ice 3 tho... since Fire 3 will have halved cast time but the Cooldown wont go for lower than what your Spell Speed allows.