I split the difference. I have a 3L Camelbak that I wear on my back, obviously, and a rack with a soft side cooler that I put my clothes and misc other stuff in like lunch and what not. Takes most of the weight off my back and the water is easier to reach and a little more sanitary on wet and dirty days. The weight provided by the Camelbak keeps me in a better posture too with my shoulders back and my back straight. I certainly notice a difference with no pack.