Recommended for first playthrough or for those wanting vanilla game with nothing else than better graphics, sounds an FX !"
Use it if your game crash during a load ! (already included in Ready to Play version)
It's the user.ltx I use and it's tweaked for better quality and gfx quality (DX10, 1920x1080), by Thales100 and it comes from his mod page (screen in the description), I also tweaked it to avoid crash !
Install it in : Documents\Stalker-COP (the same file were your save are stocked)
Or if you prefer use your user.ltx, put the slider (texture detail) like that :