I have a Northface 65 liter pack. I'm Army and have three issue desert camo camelbacks. The carriers are heavy so I took the blatter out and stuck it in the pocket inside my pack. I also have a few Nagleen bottles. But one thing I realized after I bought them is they are heavy! I have a bunch of cheapie sport bottles at home and they are much lighter than the Nagleens? I guess the Nagleen bottles are built to withstand getting hit while climbing or dropping. They are quite hard. But I'm leaning towards using the lighter bottles and I'm pretty careful about not dropping my gear. I can kind of relate to another on here about stopping to dig out a bottle as aposed to just sucking on your hydration mouth piece as you walk? Diferent strokes I guess? One other down side to the backpack Nagleen bottles..they are not cheap. I think my small one was $10. and the bigger one was $15. Yesterday one of my co-workers here gave me a free National Guard sport bottle that is perfect for hiking and its feather light. Hope my two cents helped?