Yep, that 1-2 second delay can be problematic at times, but when I "D I PRIEST" or "LAY OF HANDS" it usually actioned by the time I finish saying it. I actually rely on it for those "oh shit" times. Because I don't have the "oh shit" buttons keybound I have to click a button. With something I don't often use it can take a few seconds to even find the button and then click it. Voice is by far my prefered option.

But my "spam" spells I still key bash. Fireball and Arcane Explosion are the only 2 mage spells I press a button for. Every other spell is voice controlled. Though I do have "EXPLOSION 6" which does 6 Arcane Explosions and Fireball 3 which ofcause casts 3 fireballs. The downside to an attack sequence custom command is that no other voice command is processed until that one is complete. So if I do FIREBALL 3, it has a cast time of lets say 2 seconds x 3. So in that 6 seconds any other voice command I issue is held until the Fireballs are finished.

[EDIT] I just did a few tests, the delay is not as long as I thought. When I said "ICE BLOCK" it was less than 1 second until the mages were on ice. when I said "FADE" it was about 1 second until the priest dropped aggro. "PRIEST USE MANA POTION" was almost instant. It appears the longer the voice command the quicker it is actioning it. When I said "D I PRIEST" and jumped in the air, I had DI'd the priest by the time I hit the ground.