JoeF2661Other then gore-tex what other waterproofing is out there that might run a bit cheaper but hold it's own when put up against gore-tex?
Honestly, the vast majority of supposedly "20K/20K" proprietary waterproof/breathable fabrics I've used are on par with Gore-Tex. I haven't used Virtika's stuff, but every proprietary 20K waterproof/breathable fabric I've used from Patagonia, Flylow, Norrona, Outdoor Research, Trew, North Face, Holden, Mountain Hardwear, and Strafe have performed just as well as Gore-Tex when it comes to waterproofing. And some of them are better than standard Gore-Tex when it comes to breathability. And many other 3rd-party laminates like Schoeller C-Change, eVent, Dermizax, and Sympatex all seem on par with Gore-Tex's waterproofing.
That said, waterproof ratings are tricky. There's no third party that makes sure that fabrics labeled as "20K," "10K," "5K," etc. actually perform to their stated ratings. There are standards that determine what those ratings mean, but there's not really anything out there that regulates and monitors how waterproof/breathable jackets, pants, etc. are. It's in many companies' interests to not lie about their ratings as it'd lead to distrust, but without expensive testing equipment, it's very hard to test those ratings for themselves. Most just take the fabric supplier's word for it, and trust that the fabric supplier's testing numbers are accurate. Some of the bigger brands do use in-house testing equipment, but that's fairly rare. That's part of why Gore-Tex is a good option — they've been making their fabrics for a long time, have their own testing equipment, require stringent standards for how a company can use their fabrics in order to live up to their reputation (e.g., which zippers they can use, seam taping, certain face fabric and backer combos, etc.), and as a result of all this, have their "guaranteed to keep you dry" warranty.
So all that is to say is that, for the most part, a proprietary 20K fabric is gonna hold up similarly to Gore-Tex when it comes to waterproofing. 10K is the vague standard for a fabric being classified as "waterproof" (rather than "water resistant") but 10K fabrics can wet out in very wet environments or when subjected to a lot of pressure (e.g., at the elbows of jackets, knees of pants, etc.). When it comes to other factors like breathability and durability, things can vary a lot as a company working with their own fabric and laminate has a lot more freedom and variability when it comes to how they manufacture and use that fabric, whereas Gore-Tex limits how a brand can use their fabric in order to maintain consistency (and, in theory, quality).
TLDR: the vast majority of 20K rated fabrics will be similarly waterproof vs. Gore-Tex.