My unit was one of the first to get Gore-Tex back in the late 80’s. We got a set of light, medium, and heavy(arctic). The primary advantage is that it allows air flow. So you don’t heat up and sweat your a$s off. That and it keeps you dry when it’s pissing rain. The medium and heavy were designed for improved warmth, the light for summer use. All I know is that compared to traditional rain gear they performed as designed. Nothing’s perfect, you would heat up slightly, but nothing like the old gear that would basically be an airtight barrier that contained your body heat.
I still swear by Gore-Tex gear for wet weather purposes, especially jackets and over-pants. If you start heating up, just open up a zipper or two a bit and let some cool air flow in. No matter what type of wet-weather gear you use, eventually SOME water’s getting in. Fact.