The level that I'm at I really can't say. The people I serve with really form a bell curve. The reserve unit I'm in tends toward the more intelligent, hard working and dedicated person because of the nature of the unit.
The rumours I hear are from people I know in the service. I take them with a grain of salt to some degree, but not entirely.
I have experienced some of Steel Wolf's concerns about older folks in the service. When I was deployed to Kuwait, there were guys in my unit in their 50s (and some pushing 60). Injuries, illness requiring SIQ, etc. were much higher amongst the older Sailors then the ones in their twenties. Sailors in their 20s bounced right back whereas some of the older ones had some significant problems.
I would expect some of that in the reserves. These folks have likely been in a long time, and were caught there when war broke out. I suspect there will be much less of the single mom, or folks looking for college funding, Reservists in the near future, simply because they now understand the seriesness of their being there. I'd expect those who are volunteering to serve at this point would not have the same problems as you saw.