After a loong season with tons of skiing, my patagonia had some discolored spots, and the waterproofing wasn't as good as it was out of the box, although it was still waterproof (i just wanted to show my jacket some love). Local store told me that gore-tex specific products are worth it, so i got some wash-in product from Nikwax, and a spray that had to be applied afterwards.
The discolored spots aren't discolored anymore, but i can't give you an update on the rest of it yet, as i haven't used it. But this was the advice i was given at a solid outdoor store.