I flew Syd - Singapore return this week aboard the Singapore Airlines A380, my first flight in it.
Overall impressions very good. Had to fly economy, the seating is larger and more comfortable than my recolelction of the 747 and other long haul aircraft. Suggest sitting upstairs on the outer isles where there are two seats only, not three, and due to curvature of the fuselage, there is a bin (and more space) under the window, same as upstairs on a 747.
Re hydraulic problems, the subject of this thread, I can confirm that we were delayed by one hour out of Singapore due hydraulic problems. The pilot said that hydraulic oil was discovered on the tarmac under the plane, so it had to be checked. Much activity by the maintenance personell was evident.
Flew return sector in the downstairs aft cabin and I strongly suggest avoiding this cabin due loud hydraulic motor actator noise from rear airframe, plus much more pax traffic heading for the toilets.
But I was very impressed with the A380. It is now my aircraft of choice and the Singapore product is good. Next week I am Qantas to LAX, in economy, so I will see how that goes with interest...