It's all subjective indeed. I think that people's experiences are relative to the day and the time of day they travel - and terminal used. This can make a significant difference to one's perception of an airport. As a frequent passenger not flying on business I often fly at off peak times of the day (and the week). Consequently my experiences tend to be pretty smooth at those times, including some of the airports mentioned above. I certainly have had no issues with JFK and LGA, and those mentioned by other posters such as CDG, LAX and ATL. I can't judge LHR as I personally gave up using it many years ago. The real test of an airport is departing early morning or late afternoon, especially on a Monday (morning) and Friday (late afternoon). That's when you can judge the efficiency of an airport a little more accurately.