I have the British Army Issue P.L.C.E. Infantry Bergen
I've added a chest Strap,
A flat sewn pocket on the lid, so my Bergen cover has a place to live.
In between the side pocket zips I have 3 channels on one side (for my Axe and 2x Hiking Poles)
On the other side in between the zips I have a mesh pocket, (makes a great Stash pocket for my Goretex Jacket)
And some 3M reflective tape sewn here and there so I can find it when its dark and so Cars can see me when I'm carrying it, that's why I have the Cover (It hides the Reflective tape for when i want to be sneaky beakey.