Which Army component is the most challenging?

Based on the list, I would be inclined to say that being a TPU is the hardest. I say this because I have been on both sides of the fence for Active Duty and Reserves. By far, the Reserves is the more challenging. Being a TPU, you are expected to meet/exceed the standards and expectations that ALL Soldiers have to do, except you do a lot of those additional tasks/duties on your own time. During the monthly BTAs (Battle Training Assemblies), you are given anywhere from 2-4 days (schedule depending) a month to get everything that an Active unit has 30 days to accomplish. Outside of those days, you are still expected to accomplish all the required tasks while not on Army time. There are many times where I was accomplishing Army tasks while also accomplishing civilian employment tasks. Also, one must take into account that TPU Soldiers can have a harder struggle to get into any of their required PME courses because we have to juggle and figure out what course dates are more of a match for our civilian schedules. We also have to face the stigma that many of our Active Duty counterparts place on us simply for being a Reservist. I could go on and on....because the list is long. But, to be honest, while being a TPU is harder (IMHO), I also feel that these challenges can make for better Soldiers because of these very challenges. It makes us better problem solvers and time managers. I wouldn't trade my Reserve experiences for anything.