The first one is made of brass, heaviest, features a screwed cap so that remaining alcohol could be saved inside for next time.
The second one is made of Aluminium, lightest, this is an optional part of a wood gas stove. When we don't want to burn wood, or we don't have wood to burn, this could be nice as contingency.
The third one is made of titanium, not exactly the lightest, but it's robust. There are volume marking inside so that we can accurately control the amount of fuel to reduce wastage.
Alcohol strove is slow, but we can always bring more than one. If we use a gas stove, we need more gas canister at the same time. Similar problem with a white gas stove (白電油爐), but for alcohol stove, the stove holds the fuel too. This is yet another edge for the alcohol stove.