I would say those who have to work with the Reserves/National Guard. This handful of professionals has to try and cram a month's worth of training into a weekend, and then spend 2 weeks at Annual Training trying to make the weekend warriors into professionals. Note, I have nothing against the Reserves/Guard people, they have a tough job, balancing civilian and military life, and are increasingly more important in operational planning. I have known many who serve in both the Guard and Reserves, as well as those full time military personnel who are assigned to work with them.
The full timers have to shoulder a large part of the burden, while making sure the Reserves/Guard troops are ready when called up. There is alot of pressure to make sure nothing negative gets reported up the chain of command, because it reflects badly on the full timers, who work long hours and with little support to do a difficult if not impossible job and still manage to keep things together.
We few, we happy few, we band of brothers;
For he to-day that sheds his blood with me
Shall be my brother