Gore-Tex is an interesting case. It’s pretty fragile stuff, but technically doesn’t “wear out” or break down chemically (well, it does, but it takes a long time). Because it can’t take a lot of abrasion, however, manufacturers have to sandwich it between two layers of material. In so-called “two-ply” construction, an outer layer of fabric is bonded to the Gore-Tex, then an inner layer of loosely hung mesh material is added. In “three-ply,” an entire layer of fabric is bonded to the Gore laminate in place of the mesh. These layers shield the Gore-Tex from wear, and in the case of the outer layer contain a water-repellent coating (the DWR) that helps water bead up and prevents that outer layer from saturating, something which impairs breathability.
That is what has happened to your Mocha. The outer layer has lost its original DWR, and while spray-on materials work pretty well, they aren’t as good as the original coating and tend to wear off quickly. Maybe the face fabric on your jacket has become slightly frayed, too, impeding its ability to hold the Revive-X (you might also try NikWax’s TX Direct Spray-On, just to see if for any reason it works better). The end result: When it rains, the outer layer becomes wet and water blocks all its pores, effectively sealing the garment. The Gore layer can’t transfer moisture to the outside of the jacket, the moisture condenses inside the jacket, and you feel clammy. The cruel irony is that the Gore layer is probably working just fine; it’s the supporting cast that has failed.
So, it might be time for a new jacket. Today’s DWRs are more durable than those of six or seven years ago, so you might get more wear out of a new jacket than the Mocha. Plus, most Gore-Tex jacket makers have switched to what is called Gore-Tex XCR, which is both lighter and more breathable than the “classic” Gore-Tex in your old jacket. One good example: L.L. Bean’s Mountain Guide Jacket, just $299.