Personally I wouldn't bother with inter-city rail travel in Australia - much better to fly or drive. The standard of trains compared to Europe or even the US is relatively low. The exception of course are the iconic train trips on the Ghan or the Indian Pacific.
To address an earlier comment - Canberra is definitely not boring. But it's not a city designed for the whirlwind international tourist. It is a city built for cars, and the public transport is terrible, which makes it difficult for tourists. And it's a city that benefits from exploration with a local - a lot of its treasures are hidden (even in plain sight).
So if you only have a couple of weeks and are trying to see the highlights across this continent, it would be better to skip Canberra. You're going to be spending enough time travelling between places as it is!