I use my issue bergan all the time and don't have any real problems with it, i often walk long distances and only suffer if iv'e not been carefull of how iv'e packed it, but i'm sure it's the same with any other bag, one point though if you do look or a mil bag try and ind a long back bergan, there used to be a lot of hyp in mil circles about trying to get a short back bergan the benifit being that it sat higher on your back almost resting on your shoulders witch ment it cleared your webbing and didn't push the pouches into your skin, and if you had to go prone with it on you could still lift your head without your helmet getting wedged, also with a long back the hip belt is in the proper position to give you the right support. having a dpm bag isn't that bad as you can always cover it with a water proof cover in any pattern.