Actually we're splitting the team for our trip, because of how we had the miles spread around. It will be Mrs. Zippy and one of our little cherubs on OZ, and myself with the other little cherub on KE. We've done that before, and it was OK. So Mrs. Zippy scored the upgrade. We had booked J for the return, and happily OZ put Mrs. Zippy in J on the A350, though the seats they (OZ) picked on both legs were what I'd regard as inferior, compared to what we had selected on the A380, and we did have the hassle of a couple three calls to get the A350 seating finalized.
Regarding which is better, I can't speak from personal experience, but from what I see, the A350 ain't so bad.
TPG on OZ A350 (lots of pics)
Airliners.net thread on OZ A350 (more pics)
According to the TPG piece, there is in-flight WiFi on the A350, which might be good for some.