I have flown J 3 times (12 sectors) and in general Etihad have been very good. As a result I have never gotten around to writing a review on Skytrax. As others point out I think people (myself included) are more likely to leave a review when something goes wrong.
AUH is shambolic, however the new lounge is vastly superior imho, although why they didn't build more bathrooms is beyond me. Out of the 12 sectors I have flown I think I have only had one crew that were average, but still not bad. I can't ever remember any cabin crew being rude.
Manchester airport lounge the first two times was excellent, however last time the staff were atrocious, this was soon forgiven if not forgotten though after receiving excellent service by the cabin crew straight after.
Enjoy your trip