No leaking, because there are hardly any holes to leak from . I use the bottompeace of the 0.5 coil in a 1.0 ohm clr coil on my ego one and mega. This is a perfect draw for me. But in the egrip there is no difference between the airflow of a 0.5 or 1.0 coil. And the silicon thing on top of the clr makes the tiny airhole even tinier. Well pure mouth to lung vapers might like it and I must be honnest, the taste is amazing ... Almost like it's a totally different juice. I'll stick with the egrip rba or a ego one clr for outdoors.