chookie, thanks for your great comments.
I agree that the Syzygium species are hard to go past.

i am curious about your comments on Waterhousea florabunda, it is used
extensively down here as a medium screen.
For example here is a typical comment from a melbourne retail supplier.
Maybe it is a matter of getting the variety correct.

http://www.goinggoinggreen.com.au/trees-melbourne.html