...some thoughts.

Hydration bladder systems like CamelBak are great for taking quick sips and for carrying water high up on your back. you can carry quite a bit

Drawbacks -- harder to load than a bottle -- its a flexiable bag. They sometimes leak or break, though not often. Must be dried between uses and may hold onto the taset of your beverage.

Overall, highly reccomended. I have both a butt pack and backpack model. ( They also make it easy to carry everything esle along on a hike.)

TRO