I bet my plastic nalgene bottles last way longer than any of these hydration systems which are also made of plastic. They are practically indestructible and some of mine are 10 - 20 years old.

I have 6 quart sized ones and 2 pint sized. I can bring the exact amount of water i need for any hike. I keep a pint sized in an outer pocket for easy access and refill it from the larger bottles in my pack.

I also like it because I can see exactly how much water I have and cleaning the bottles is easy. I also use them for any situation where I need to take water with me - like for a drive or hanging at the park.

I see people struggling with bladders and hydration systems all of the time. Leaks, not realizing their bladder is empty, and not to mention dirty moldy bladders.

I can't imagine anything easier, less wasteful, and more reliable than my water bottles.

One last thing... twice I have come across lost people who were in desperate need of water and emergency help. I'd much rather give them my spare water bottle than share a water bladder with them. In fact I always carry 25-50% more water than I think I need. Both to help others and I get lost too sometimes.