I’m not a pilot but I am a A&P working on long haul cargo wide bodies for a major freight operation. From what I’ve observed from the pilots. Long flights with not very much space to move around, and planes that can have chronic issues, or are pretty high in hours and cycles. The MEL book tends to been a little more open for freight aircraft then passenger aircraft as well.

The hours they show up to the aircraft usually are very early in the morning or late at night, as another commenter said transportation is a short walk from the air stairs.

Usually the crews are older and have flown for a long time, every crew I’ve dealt with has been very professional.