- the gyre powerheads produce a "laminar" flow pattern.
In simple terms it means that the pump pushes water out in a sort of sheet. The area of flow is as long as the powerhead is.
-The vortechs produce a more conical flow pattern. This is better for targeting specific areas of the tank as opposed to the whole length of it. The vortechs also have more flow modes and a better controller.
It really depends on what tank you have and what you like. I have a 60g cube and I have the icecap 3k. I have no deadspots. Remember, you don't need to buy expensive powerheads for your coral to grow.