Ahh, see I was thinking like a dewar. Air is a great insulator. How do you think dewars keep your LN2 preserved :)

ok, think I'm following yr thinking now, but, isn't the liquid in the outer chamber required to suck some of the cold out of the inner chamber?

I have no idea. :)

me either :P but I know the you pay through the a$$ to get the clear outer chamber, so that would be reason enough for me to use it like Buckeye cause it looks so cool :D