I worked for EK for quite a number of years. I found that on certain flights, the cabin would be lit up like a xmas tree. Before a flight, you just knew you were going to be running around like a headless chicken. The airline I work for now is totally diferent. We are always full, we fly to similar destinations, but our pax are angles. Hardly ever hear a peep. When a call bell goes off, it is answered promptly. Some pax are just far more demanding than others.