Thanks, all. I think a little cropping is OK, but the crop k suggested is too tight for me: I like to see the ground. Russ, I agree you've improved it!
As to quality, alas, I took this, with my first digicam (a Konica-Minolta A2) a few years ago, before I learned of the virtues of raw. It's a jpeg and it's already pretty heavily cropped (down to about 4MP). I've no doubt I'll revisit Sydney in the next few years, so I'll re-take it properly then.