The question of bringing the bottle full of water is an important one, but it mostly depends on what you plan on using the bottle for. If it is a pot that can be used as a water carrier then you carry your water in other devices. I am one of those who thinks that under most circumstances that a cooking pot is very important. I have 3l of water in my bladder and another 1l bottle, the additional water is not necessary in most environments. My extra bottle is a SS Guyot Designs with a 700ml Snow Peak pot around it so I carry my gear in a soft bag, but if you use a plastic bottle, carrying the survival gear in a metal one is a great idea. As a pot to carry the gear, it has the advantage of being waterproof from the outside as well. The bottle in the original photograph appears to be a Guyot Designs bottle (or their bottle branded by others including Nalgene). I think it is about the best bottle available (Ti would be better but they are out of my budget). Drilling two small holes in the flange (not part of the sealing system) allows for split rings or a wire bail. All of mine have this mod so that they make good pots. It is possible to add a bail without the holes, but it is much more simple and uses lots less wire if you drill them.

If it is your only water carrier, or you do not have enough water, I agree it should be filled with water, not gear.

Respectfully,

Jerry