The one downside to my trip was how short it was. Australia is a big country and the Great Barrier reef is the largest living organism on the planet. Two weeks just can't do either justice.
What I did would have been the equivilent of coming to the US, spending two days in NYC, go to a broadway show, then fly to Vegas. Spend a week backpacking the Grand Canyon, going back to Vegas for a night and then fly home and say you have seen the USA.
I'd recommend Australia to anyone who can afford it. Yeah, the flight sucks. And the 40 hour day on the way back with 30 in transit is pretty bizarre. Thank god for Ambien. But given a chance to go back I will. THere is too much else to explore and see both diving and on land not to.