The problem with "Instant OFF GCD" abilities makes combat feel less rewarding.

[Hirosashi]

I think when your skill say Cast: Instant, you generally thing its an instant ability ... or maybe I am wrong :S

Instant cast does not mean there is not an animation or effect or even that the effect with be applied instantly it simply means there is no cast time. Being able to apply 6 dots in an instant would just be broken, it would take all the skill out of chaining off-gcd and on-gcd abilities together to make a good attack chain.

A good example is thunder to aero, cast thunder the nano-second its down casting you can cast aero bam, two dots on the target at the same exact time, thats how you chain effectively. I dont know of any dots that are off gcd lol so aero was all I had there.