I just found this thread via google while looking for something else, so I'll follow-up here as well.
Gore-tex and Dintex are for all practical purposes identical in theory. The patents on Gore-tex recently ran out, so people are free to replicate it. The trademarks on Gore-Tex, however, don't expire, so you have to call it something else.
For those of you who don't know the particulars of Goretex, its a teflon film membrane underneath a protective outer garment layer. The teflon layer is what "breathes". It has pores in it that are too small for the surface tension of water, so liquid water cannot pass through, while water vapor (that comes off your filthy body) can pass through as your sweat evaporates. This membrane is very thin and delicate, so there's an outer layer of nylon or polyester, this is the outer layer you see when you look at the garment.
The outer layer has to get treated with some kind of water repellent to keep it from being saturated when it rains, because soaking wet fabric doesnt breathe.
Much like Gore-Tex itself, there is huge variation in the quality of both the outer layer fabric and the water repellant coating on it depending on who's making or selling it. This is what makes or breaks the quality and durability of the garment, not the underlying teflon film.
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