Air conditioning was corrosive and smelt badly almost like stale cigarette smoke. Many passengers coughing badly by end of flight. Subsequent sore throat and chest infection to persons who were completely healthy before flight.
Flight attendants poorly trained and incompetent; several passengers not checked prior to landing and two passengers within view did not have seat raised to upright position during landing; empty cups from coffee service not collected and had to be taken to toilet to dispose of them.
Passenger not checked for their height and weight. Passenger in seat behind so big that seat could not be reclined at all in an over night transatlantic flight.
Food at best could be described as tasteless.
In flight entertainment on international flight but lax flight attendants did not distribute earphones and most people therefore did not have sound for the films they were trying to watch on an 8 hour international flight.
The health risk obviously the most significant and serious risk.