So far, the one modification I've made includes the contents of the PSP, without the orange pouch, and put them in one of the two wing pockets. All outside pockets are zipped and watertight.
I was not too fond of having the contents of the PSP lose in a pocket, even with the pocket zipped.
I put them back into the orange pouch (which almost fits the exterior pocket) and put it with the water filter. I imagine the PSP would fit the wing pocket if it were still in the clear pouch.
Jeanette Isabelle