Just to make sure everyone is on the same page, Gore-Tex is a laminant. If the Gore-Tex gets a hole in it, no amount of spray or putty is going to repair the Gore-Tex. now you can make a case for making the material that the Gore-Tex is adhered to waterproof, but you will never get the Gore-Tex itself waterproof again. Think of Gore-Tex like a plastic bag adhered to the inside of your coat/boots/gloves that somehow breathes (thus the magic of GoreTex). Rip the bag and you are out of luck.
^What he said^
Properly constructed Gore-Tex stuff with taped seams lasts a long time. I've got a Cabelas coat so old it's made in America(!) and it's still completely water and windproof. Same for my old Danners. A cheap Woolrich jacket with no lining now leaks at the seams because the tape was unprotected and is coming loose in tatters. I was under the impression that stuff wearing the Gore-Tex label had to be built to their standards, but who knows now?
Since Gore-Tex is laminated to the outer layer of fabric, I'd be careful about what I sprayed on it for fear of futzing it up. I've used some spray-on stuff on regular fabrics, but it's never done much or lasted long.
