The problem of course, with the PS20, lies in the way
Deus Ex treats
weapons in the game. You can't pick up a
weapon, if you are already holding one of the
same type. This
makes sense with most weapons, since the version you are holding will always be
at least as good as any you find on the ground, and will probably have
mods to improve it, whereas you can
never find a weapon with mods already on it.
This does however rather (unrealistically) hinder the PS20. It only takes up one square in your inventory, and looks very small, yet you can only ever be carrying one because the game prevents you from picking up a weapon you already have, if you try to acquire a second one. It can therefore only be used as an absolute weapon of last resort, since you can't even carry a spare spare, so to speak.