>>1179106I have used skybus, and would have to agree with your friend that it's "good enough". It still gets clogged in traffic during rush hour, but that should be easy enough to solve by adding a bus lane down the Tullamarine freeway. They're also right in an airport rail line being a low priority right now, but seeing as how Turnbull is willing to cough up some cash, we might as well take it. Personally I just don't like buses because they're slow, unreliable and trains are (in my opinion) better in every single way.
Personal grievances aside if the route does end up being along Albion-Jacana, I would hope that it ends up being a dedicated track pair into the city as there's space for it along the existing right of way. The direct route does have benefits as you mentioned but I'm not sure it's worth it - the extra billions it would cost would be better off towards Metro 2 or extending the electrified network, like Melton or Geelong.
Regardless of route I've seen a interesting gunzel proposal to not stop the line at the airport and instead run north and split into two branches towards Wallan and Gisborne. Bendigo and Seymour trains could then run via the airport. In the shitty ms paint picture attached I've mapped it out - purple = existing V/Line route, red = new route via the airport (green), and blue = extended metro services to provide interchanges at Gisborne and Wallan.