Out of everything I have tried, I like vaping DCT tanks the best. I have been using a smok pyrex DCT. I am having constant leakage problems from the bottom. Does anyone have any experience with this? Before I buy another one, does anyone have any suggestions for a different high quality tank other than the smoke pyrex? I found a website selling "Big Daddy" & "Big Mama" tanks. Are these tanks any good? are they pyrex or poly? They are kind of expensive. I don't mind spending the money, but I want to make sure I am getting a high quality tank that is easy to maintain if I need to replace o-rings etc...anything else I should be looking at?