I guess you mean this one:
Personally I wouldn't be super comfortable putting any pressure in a mason jar for a couple of hours, although I expect the lid would fail before the glass. Irrespective of this it is not (like
TheBeerBaron said) better suited 'out of the box'. Also I am sure that the people that purge seven (or twenty) times would likely complain that the method did not get rid of all the oxygen and did result in oxygen contact.
I think it would be great for the next person that wants to compare the FZ to another product could create a comparison thread for that, then the half a dozen people interested could keep track of that, and we can get back to talking about using, cleaning, and maintaining our fermzillas without having to endlessly and unhelpfully have them compared with competing products.