Coming back to the origanal question, i flew with F/E"S on the Tristar for four years a while back, and miss them a lot. As previously stated they are a walking VOL 1, generally, very good on the social circut, and useful for repairing the girls hairdryers, and hotel kettles!
However as a young F/O you often needed thick to put up with the banter until one had proved oneself competent in his eyes!
Looking back with the benefit of hindsight, a good F/E was worth his weight in gold, and the bad ones, who were usually wannabee pilots were a liability. I can still remember 2 occasions when a short, muscular and rather hairy arm came onto the power levers to save the day