Rating: 5 / 5
Five of us took a Platypus 6L reservoir on a two-week trek. It was the handiest thing in the world for hauling large quantities of water to our camp. It has webbing handles, it was easy to fill, and it sealed well. Note that we did not use it to carry water in our packs (we each carried two 1L platypus containers for that).
Each night we would fill it up and add a low dose of Aqua Mira and let it sit all night. The long dwell time allows you to use a smaller amount. In the morning we would transfer the water to smaller containers and off we would go.
We found it indispensable.
Spread over five people its weight of 3 oz (90g) is not much. Platypus also makes a 4L reservoir that is somewhat lighter.