I used to work in the CBD and DH works at Tulla. When we were looking at buying, i looked at the train system pics, including vline and had a look at towns/suburbs along the lines. We looked at a few areas along the hurstbridge line, but then ended up buying along the mel-syd (vline) - extension of broadmeadows/crazyburn line. This wouldn't help you if you were at deakin, but is great for access to the cbd.