By Cerberus.Mindi 2012-12-17 12:39:27
You can start a magic in fastcast/casting time- equip and change it to potency gear midcast so you end the cast with potency gear for max dmg.
But if you want to lower your recast, you would need to end the cast in haste, fastcast or recast- equip.
Fastcast works on both phases of a spell, to actually lowering its castingtime and to lower it recast time. For example - 10% Fastcast will give you 10%fastcast for the casting time, and 5%recast.
For elemental magic normally dmg is your maingoal, since you can just cast another spell to do dmg until recast is ready. If you are casting stuff for procs you can stack haste/fastcast/recast equip since in that case dmg wont matter that much (or you even want to lower your dmg to proc weakness on weak mobs)
especially magic like stun you want to add as many fastcast and haste to finish the spell as fast as possible while still haveing enough MACC/Skill to hit stun on the target you cast.