Expo
The communications in the lead-up were kind of confusing about whether there was an expo or not, or whether you just go to the office to pick up your bib. Turns out there was an expo outside the MCG; it wasn't super busy though possibly because Australian entrants could have their bibs mailed to them. I registered way in advance but didn't get my name on my bib while plenty of others did, so I'm not sure what that's about. I asked about shirts and they said there were none.
Course
Super flat, but pretty dull. Plenty of out and back sections so you could see other runners, and then an annoying detour into the Botanic Gardens on the way back to the MCG. Lots of missing km markers especially at the end. Plenty of water at each station, but overfilled cups made it all very soggy. There were two stations with gels (Maurten) which were great and I will definitely buy them in future. There were some merging spots with the half and then the 5km or 3km, but they tried to keep those distances separate. The stadium finish had separate lanes for all the distances. I imagine fast runners would have had issues with the merging.
Atmosphere
Eerily quiet for the second largest marathon in Australia. The few spectators out on the course were only cheering the people they knew. There were maybe 3 spots playing music. The only part of the course with any sort of atmosphere was the last 500m into the stadium where there were actually people.
Post-race
For marathoners you went straight to bag pickup, to get your finisher shirt, and there was a changing room too so that was really smooth. However they were running out of smaller sizes - not surprising, because they never took your size preference during registration since it wasn't clear whether there were going to be shirts. The general lack of enthusiasm carried through to the finish - I had to ask someone for a medal because the people handing them out weren't paying attention to who was walking past. They only gave out cups of water/Gatorade (no bottles) in the name of sustainability even though they handed them out at the expo the day before, so I was pretty parched. They also had zero food - not even an orange segment or banana.
Overall, it was fine - helped a lot by the perfect weather and the flat course but the complete lack of atmosphere was a bit unexpected for a big city and the field size. I happened to be in town so did the race, but wouldn't travel for it. The were some oddities with the organization especially if you're used to overseas races where shirts and post-race hydration are always included.