Metrobus was started by the previous government, with an obvious agenda of visibility as part of its plan to attempt to at least arrest the degree with which they were to be booted out of government.
So what is good about it? Firstly, a real bonus from Metrobus has been increasing the capacity of the vehicles. The current restrictions on non-Metrobus buses within the STA are pretty absurd: a standard size bus is only allowed 15 standing passengers for 58 total passengers. Even a bendy bus only allows 88 total passengers in Sydney Buses, but a Metrobus bendy is allowed 115 passengers aboard. While there are some slight changes to the interior seats, mostly this change is simply a matter of policy. It would be good to see this increase spread to other buses.
Secondly, overruling Treasury by actually providing public transport at non peak times is a real positive. An improved services is now provided on some cross town routes (M41, M54, M90, M91, M92) which otherwise would have been left to rot on an even more mediocre service. Similarly, the frequency upgrade for the L20/M52 and 600/M60 is a positive.
What is bad? All of the original routes (M10, M20, M30, M40, M50) have design issues. It seems unlikely that they are money well spent for public transport in Sydney. Other routes do not offer services after 9pm and have only 20 minute frequency after the evening peak and on weekends. Shutting down at 9pm hardly makes the service dependable, and while the 20 minute evening frequency is arguably acceptable, it is less acceptable weekend daytimes when traffic congestion is still quite bad. The 520 which replaces the M52 after 9pm runs approximately hourly, which isn't exactly good.
With the M10, it seems that the money would be better spent on increasing 39x and 436-440. Only counter would be layover space in the CBD, but this counter cannot apply at weekends and evenings.
M20 does have a real positive in connecting Bourke St and the top of Joynton Ave with Central. Conceivably, this service could be provided by moving the 302 & 303 or 301 to serve Central, and increase the frequency. Moving the former pair of routes would also connect Todman Ave to Central which does seem like it should equally be a winner. The other side of the M20, the Pacific Highway already has plenty of service, and the increase here seems overkill.
M30 provides an increase along Military Rd which is surely useful, however the other side completely avoids most potential passengers who would be waiting on Castlereagh St. While it may well pick up a number at Railway Square and get some through passengers, this route seems to be a bit misguided on the south side.
M40 is like a 272 connected to Bondi Junction. So perhaps south/east bound use the Cahill Expressway, extend to North Bondi and serve 333 stops, as the passengers bound for Bondi would be found on Elizabeth St? I can live with a bias to Bondi passengers, with a side benefit of serving the eastern side of the CBD with respect to 272 corridor passengers. Given that there are a large number of 272 passengers, it is likely there will be several takers for the M40 serving Elizabeth St on the Willoughby side during peak hour.
M50 is the worst of these in my opinion. While this does connect Coogee with the University of NSW and the University with Central, both of these functions are already performed by routes which already exist. It also connects Drummoyne with the city and provides a through route to UNSW. Increasing the 370 between Green Square and Coogee would have done far more good. Even the load factors are slightly below the all Sydney Buses average. The good point about the M50 is serving the inner part of Victoria Rd, but I am sure that could have and should have been done by increasing 5xx series routes.
M52 is the best performing of the Metrobuses, getting nearly 60 passengers per trip on average. This is roughly a doubling of the frequency of the old L20 so it's not really a new route at all, just a frequency increase and a rebranding.
Service kilometres have increased with Metrobus, but STA's overall patronage hasn't. Similarly, Park St congestion has been AIUI significantly worsened by these changes. While there are clearly good services, the case seems pretty compelling for reviewing some of the network.