I've just bought the Gore Power Active jacket today from here.......
http://startcycles.co.uk/gore-bike-wear-power-active-gore-tex-cycling-jacket-black.html
though from the shop rather than online. I've just returned from an hour or so of quite strenuous (by my standards) cycling. Apart from a slight shower for a minute or two it didn't rain so I can't comment on how waterproof it is. TBH, waterproofing has never been an issue with Gore Tex so I'm convinced this will not be any different. Its the same with windproofing,any waterproof fabric will be windproof and this jacket did not disappoint, in blooming strong winds
Obviously, physical activity make me sweat but I doubt I sweat more than any average person. Tonight my hair has soaked, so I knew I'd pushed myself. When I removed the jacket, I was pleasantly surprised at how little perspiration there was in side. I only detected a tiny amount in the arms, which I consider to be an improvement on all (including my beloved Paramo) other breathable waterproofs I own.
Minor gripes time, The smart phone, plastic bag is a joke, my Galaxy S 3 with a Seidio case doesn't fit! I would have liked to see an elasticated draw cord around the neck as it's not a snug fit and could let rain leak in. At the minute though, I'd say it was a very good investment and I'm really pleased with my purchase
I have a Gore Gore Tex and the rain penetrates the zip when it hits from the side. I think they're fine for lightweight showers but persistent stuff will eventually get in, never found one that kept me completely dry. Yours is a newer one though, be interested what you find with it long term.