Outer T2 is completely fudged. With every service having to be all stops that means 1 hour and 15 minute journeys from Liverpool to the Sydney CBD. This is why I think the metro should be extended around the existing T3 to Liverpool instead of building an expensive creation that will be tunneling from bankstown to liverpool via the milperra road corridor. The all stops metro is 10 minutes faster then the all stops ST service to bankstown and it goes to reason that it could be another 5-10 minutes faster from bankstown to Liverpool. This should work out to a 45 minute service.
My problem with the bankstown metro has always been that it ended at Bankstown with maybe a future project to extend it to Liverpool along the milperra road corridor. I say extend it to Lidcombe or extend it to Liverpool. Preferrably the later at the very least. It's not like there isn't plenty of room to do some extra grade separation to allow Metro, ST and freight along this corridor. It will only need a small tunnel section from Birrong to west of chester hill or maybe leightonfield. From here it can go above ground all the way to Liverpool.