As someone who only ever sees the WACA on TV the thing that annoys me most is their sight-screen arragnements.
They've covered seats in white/black material but not high enough so you still have to move the sight-screen to get the ball coming out of the white background. This was the cause of the delay the other day as well.
During the World Cup all venues were required to block off the whole sight-screen area so that nothing needed to move. Best practise was enforced. And yet the venues aren't willing to continue this on afterwards. Why CA is happy with this arrangement, I don't know. Moving the sight-screen slows down play (not usually by 17 minutes but still!).
Advertising revenue would be my guess. The sight-screens are prime advertising space, they become massive billboards every alternate over.
I guess that's why they are so heavy and need an electric motor to shift them on their tracks.