The concept of pure healers

[DreamWeaver]

Actually, the buff on Diurnal stance is a 5% attack speed buff. If I recall correctly, the lilies were described as shortening cast times. If this is a literal description, that's way bigger than the attack speed boost. I know it seems silly to nitpick this, but attack speed is a stat that calculates a number of things including cast time. Just straight chopping off 0.125 seconds (if the buff is indeed 5%), is more than what the attack speed buff is calculating.

Of course, this is all hypothetical.

Attack Speed is same as casting speed in this game FYI, you can easily test it, check your GCD before Diurnal and after Diurnal.

Additionally the 5% GCD reduction is AFTER the reduction by Spell Speed, just an interesting thing to note.