Fonck and others:. .Just to add a little more to my observations, the airline I flew for operated (over the years) the Convair 880, B707, L1011 and B747. The use of armrests was actively encouraged for all these types and on a check flight if the armrests were not in the down position for all phases of flight and with your elbows on them ,then it was an automatic mark down. I remember all my instructors including those from Lockheed and Boeing saying during endorsement " use the armrest ". Personally, I found the armrests made me feel more secure in the seat and I liked that feeling. However, it seems that they make some pilots feel trapped which may be the reason they opt not to use them.
Prince of Dzun