A few years back when getting ready for my first mountain run, I did some "jacket research." Everybody said I had to have a Gore Tex jacket to get my "a$$ over the pass." My running partner is getting ready for her first 100 miler this spring, and so we revisit the topic. She said that the jacket I recommended wasn't Gore Tex, so she passed on purchase. I said "sure it is"....when in fact it isn't.
Gore Tex was the first water resistant, breathable material to mass market. Prior to the invention, plastic ponchos and rainwear kept rain out, perspiration in. Think Sauna Suit. Since Gore Tex, other materials have come to market. North Face sells Gore Tex, but has its own version called HyVent. All use different, but comparably performing multi-layer, polyurethane and similar coatings. Water resistant, but breathable to a greater or lesser degree. Sweat too much, not enough ventilation, sauna suit again.
Opinions vary. This fellow did his own product testing by wearing jackets of various types over a cotton tee shirt in the shower. Even though article a bit old, I ended up with the North Face Venture series jacket and pants. Reasonably priced, self storing in small size bundles.
Other technologies and name brands exist. I have a Mountain Hardware Gore Tex jacket (eBay...cheap!) that is just a bit heavier than the North Face HyVent. For really cold days, but a bit heavy to carry. Almost every vendor has a water resistant, breathable product now. eVent, AquaStop, others exist. See comments "Is Gore Tex Still King?"
Price is a factor. Gore Tex is the premium brand and many say its latest incarnations have maximum breathability. But other vendors will say their products are just as good. As with anything, your mileage will vary. Most products will be water proof and breathable, but I find individual tastes vary on weight of fabric. Buy from somewhere with a good return policy.
-Larry
