I agree, too much airflow ruins the density and thickness of the vape with average builds/wattage, for me i vape on the Griffin with airflow half way closed most of the time and already think that the Griffin is too airy for my liking (the only con i find), and it would only get worse with the Gemini.
Problem with gimmicky features is that they look good on paper but have many flaws in practice (if it is not broken don't fix it), the UWELL Rafale is an example, that Anti-Spit-Back system they added to the chimney is killing the flavor and people are still buying the Crown and totally ignoring the Rafale despite it looking better on paper.
Did you get the Black Griffin? how is the finish/paint like? is it durable enough? the last thing i want is paint chipping off in my liquid, the stainless steel is very clean and healthy to use, but i like the way the black looks if paint is durable.
Will check the Diablo for sure, thanks for all your amazing recommendations, my vaping life is improving a lot because of them