I dont see how a cramped chamber with added airflow makes anymore difference then adequate airflow and a chamber that is more open...The Gemini's design does nothing extra or better then the Griffin, the added material is also its design flaw, it restricts the air and top airflow is just compensating for the loss of free moving air.
The top airflow I cant see being much help for flavor as its directed to the top of the coils but when you inhale it will force 90% of the air straight into the chimney rather then going under the coils, you will be receiving more air but the flavor would be diminished as its not going to wrap around the coil and then head upwards.
Anyone who has taken a physics class will tell you the same, low pressure and hi pressure zones will create their own force and air will travel in the direction its moving towards, air around the chimney base will cause low pressure and any and all air in the area will follow, even if its traveling the opposing direction.
Top Airflow is a gimmick and nothing more, it does not add anything to the experience, users may "feel" it helps but its a placebo effect.
The Griffin is a simple yet effective design and the Griffin25 will be highly anticipated by most, the only thing that is changed is capacity though, the deck is the same but without the threads on the sides, so Geekvape somehow can say it increase by a millimeter in deck size....
The Gemini is just a Griffin with added gimmickry and a more complex design to accomplish the exact same results...
You will have to decide which looks and feels better for you and then pick up what ever you choose, they are the same damn thing.
