I vote for getting rid of the hard plastic bottle and the metal ones.

Lets start with the metal ones. I used to use metal fuel bottles. Even though I keep my fuel in seperate side pouches on my pack, I managed somehow to hit the bottle hard enough that it devoloped a pin hole leak which I didn't detect right a way :-?

Now I use the Naglene fuel bottles. Metal is also noisy. You spring a leak in the bush it's harder to repair unless you have the right stuff.

Hard plastic is a little better, but they don't have any "give" while empty and don't pack away as easy as the Naglene, which also tends not to roll or be a loud as either hard plastic or metal.

For car camping or workout bottles it's a personal preference.