Talking about the 901, I was looking at using it on Friday, depending on when my flight lands vs when my vline train leaves. Do they have somewhere to charge myki at the airport? I tried doing online, but it no longer accepts foreign credit cards (nor does it accept my Australian Citibank EK mastercard).
My (very personal) complaint is they don't have a regular bus to Sunbury that connects to/from vline trains on the Bendigo line. That would be handy, as its only 20-30 mins to Sunbury, vs the long detour via Southern Cross. Although if paying $18 for skybus, and train fare $7 more ex-Southern X, a taxi to Sunbury may be better.