So my one experience was on a qantas code share so I had no idea I was flying Vietnam airways...
so I had the front bulk read row where there 3 Seats.
I was on far right.
A mum sat on the far left then had her 2 kids in the row in the middle..So of course she ignored them and they fought the whole way, well up to one vomited milk all over the floor.
the bathrooms were in the bulkhead in front of me.. 15 min after take off some people grab one of the drink cups to make a shield for the Smoke detector so there was a smoking room for the flight. So the whole thing stank for the whole flight.
Staff were not seen for most of the flight.
food was Bad..
When boarding most people looked to have been to the vic market on way to airport, the amount of food that was being put in the overhead lockers was stunning, so that nicely added to the aroma.
So yeah by the end of the flight, between smoke, milk vomit, lots of foods that have sat out for 10-12 hours plus some weird fish for the meal, what an aroma.
Lets just say from that point I checked code share flights after that.