We only travelled off peak, the same as I do at home. Score, pretty good. Punctual. The trains are much bigger and carry more people, mostly eight carriages compared to our six and theirs are double deck. That central grab post near the doors is great. Forward/backward seating could be better or just forget about it and get the max number of seats.
I think we travelled on three different trains. One was an older non air con train, with glass windows and had good visibility. The other two were air con trains, one seemed to be older with a different air con system to the newer one. I seem to recall another non air con train from the past that also had the plastic windows. All seemed to suffer from the same problem. That awful plastic/perspex on the top deck. Viewing out was hard through the clouded and scratched plastic.
Staff were like most public transport staff, some great, some very perfunctory, but they all responded well enough when we asked something of them.
Museum Station is marvellously old but the steps!!!! No escalator nor lift in an underground railway station. Absurd. A lot is to do with the topography of course, but Sydney is much less disabled and old people friendly than Melbourne.
It is a bit annoying that the Eastern Suburbs railway did not go through Museum Station. While I can see why and that there are benefits, I don't like isolated bits. It is very good that the trains go both directions in the underground part of the train system. I wonder what Melbourne's city train loop would be like with trains in both directions? I expect a lot more could be done with it. If dual tracks are very useful it is a disgrace that our system, built comparatively not that long ago, is single track.
The train to the airport is very good, and so it should be for the price you pay. I understand that the airport station is privately owned. Not sure about the rest of the line, but if I get on a government owned train and travel from a government owned railway station using government owned infrastructure, I expect to pay normal prices. That just to go through a gate and pay such a price is wrong.
Still expensive or not, Sydney is one giant step in front of Melbourne there.
In summary, a pretty good system from my viewpoint.
What struck me every time we caught a train was the number of staff. A static guard was on every train we caught and checked by getting out of the train that all was safe for departure and on many minor stations were staff to flag the train off. Staff were plentiful at all city stations. I was very impressed. Overstaffed? Maybe, but it made for a much better system from my viewpoint.
Like Melbourne, Sydney's trains are under huge pressure by passenger numbers, although I bet, as is the case in Melbourne, they used to carry higher numbers. I can recall from my last visit to Sydney, the alarmingly crowded Town Hall Station. It looked like a disaster ready to happen and I suppose it is worse now.
While it might be different for everyday peak commuters, my experience of Sydney trains was very good.