Until I got the Hydrospeed I struggled with a comfortable way to carry more than one water bottle but less than a 70-100 oz bladder while running 2 hours or more. Belt bladders were uncomfortable and even one bottle in a all the belts I tried tended to bounce. The key to the Hydro is a thin and relatively stiff foam on the back and the angle of the bottles which rest well and steady and also make bottles easy to retrieve. The 2 front pockets are large enough for several energy gels and a camera or cell phone unlike most front pockets. The bungie holds a light shell securely.