First of all, what criteria should be used to describe "BEST"?
Tanks are really very simple beasts of burden. Their primary job is to carry e-
juice liquid on our batteries without leaking.
They in of themselves will not produce more vapor or throat hit. Pyrex glass, being a totally inert substance, will not add or change the flavor of the
juice in any way, which is a good thing. Pyrex is also immune to the destructive reaction that some flavors have on polycarbonate plastic.
They can be manufactured to look rather handsome or pretty on our APV's. Some are actually one of a kind pieces of art. Some are somewhat easier to fill or assemble than others.
I have a personal bias against any tank that still uses polycarbonate plastic as the tube material. I feel that it is an inferior product; it is susceptible to certain flavors which will break down its chemical components to crack, melt or leach substances into the liquid.
A few sensitive individuals claim that they can taste the plastic when they vape. I find it amazing that some manufacturers of high end tanks can make beautifully machine-milled titanium and stainless steel endcaps, only to then add a cheap piece of clear polycarbonate plastic tubing to complete the tank. Tanks this fine need to wear pyrex tubes.
One can find $10 tanks that functionally work just as well as an $70 tank. Other than differing in the amount of human hands-on labor, how much do they really differ from one price extreme to the other?
So, what criteria do you use to call something THE BEST?