Seat cushions, no doubt. My Stressless Ekornes is wonderful. €2000. When B767 came out Boeing triumphed there seats as a revolution is design and had been developed by 'the pilots'. They were rubbish. The cushions collapsed in a few months and the companies refused to replace them. Pilots' unions did nothing. B737NG was no better. Airlines trumpet how good their pax seats are. Mega bucks spend on them. The pilots' seats are not important. It is time for a revolt. Tech log the seats and demand new cushions. It is a disgrace. Get rid of the stupid wool covers. Sweat generators.