One of the most powerful projectile base weapons, though inferior to the Storm Driver Turret in damage output. Compared to the Wave Driver Turret, it has more firepower and better damage to weight ratio. Fires two shots at once with a small spread which doesn't seem to matter much at medium range, but increases chance of hitting a high range target with one shot at least. Comparing to Gladius or AP Driver turret, the Gemini has the same range, with better damage output, replacing all Gladius at least with Gemini is reccomended. However, AP driver still has piercing, which may give it more overall dps than Gemini, but is not very likely. Replace at your own discretion.
The biggest sheer advantage with this weapon actually occurs when you pair it with storm driver turrets. They can unleash a barrage of fast projectiles which are VERY difficult to dodge, due to the fact that their firing patterns differ, and are harder to predict when there are multiple of them. Mixing some of the Gemini Turret III with Storm Driver Turret III can be a major increase to your bases strength.