Tidalwave -you have indeed been lucky. Maybe you don't live in a very humid environment?
The definitive GoPro anti-fogging topic -14 pages http://goprouser.freeforums.org/stickie ... ng-t6.html
This from Rambo the GoPro guru who moderates the site-
'Two things that will ruin your video more than anything else, water droplets or dried salt on the lens and fogging from the inside caused by the heat generated by the GoPro and cool air outside.'
RainX helps with water droplets on the outside of the housing lens.
Antifog can help with condensation on the inside of the housing lens but the best solution is to dry the air inside the case before closing it such as in the aircon stream.
The fogging I've had has been due to the camera heating the humid air trapped inside the housing. It condenses inside the lens because glass is a better heat conductor than polycarbonate. If the air is dry inside the case then no fogging occurs.
Other remedies include adding various moisture absorbers or in the case of the aluminium foil a better conductor than glass so droplets form on the foil and not the lens.