What does Spell Speed do for a Summoner?

[Muzy]

Your FC is correct, it will only affect spells with a cast time, eg ruin, fire cure etc. and not instant cast spells like bio, aero and scathe. It also won't affect DoTs.

It doesn't affect the animation speed or anything, but it does affect the GCD, so by extent it does affect the instant cast spells, just not nearly to the extent it does those with a cast time.