Earlier this summer I bought a Viper 7 Osprey daypack with hydration system at Escape Outdoors in North Sydney. It has traveled 50km to date and is a lifesaver when hiking 20km in 30° weather.
The bladder holds 2L of water and is removable. This allows me to take it and use it in my larger pack when I need to take a little more with me, as I did the other day guiding 5 people to North River Falls.
The best thing about the hydration system is your water is held close to your body and high up. This allows you to carry 2L of water without barley noticing. The water is drank through a flexible tube which feeds from the bottom of the bladder and has a magnetic bite valve which is easy to use and clips to the chest strap on the pack when not in use. Because of the ease, I find myself drinking more on a hike than I would normally… which is good.
I do find the Viper 7 pack a little small but is perfect for short outings where you are only taking snacks and some sunscreen or biking. I think paired with a good lumbar pack, it would be perfect.
At just under $100 it is no cheap buy but with the added benefits of the hydration system and the lifetime warranty, which comes with an Osprey pack, it is well worth it.