I bike cross country in the NE USA. I have been using this pack for three years. Previously, I owned a Camelback Stealth, which is much smaller, for two years. I greatly prefer the Osprey. Mostly, this is because the Osprey has more storage but is equally compact. Believe it or not, I squeeze a micropump, spare tube, compact rain jacket, bike tools, small first aid kit, wallet, cell phone, keys, 3L of H2O, and 1500 calories into mine. This constitutes everything I need for up to 8 hours of riding. The Osprey also looks cooler than the Stealth, allows better back ventilation, gives more H20 with less effort, and has a more durable bladder. Additionally, this pack is very well constructed. Mine, though dirty, is still as good as new after three years of abuse. In fact, the original bladder has only now begun to lose a little bit of water, although I think this is only through the bite valve. If I have any complaint, it is the bite valve. While it is easy to use (I love the magnet), it is also easy to bite through if you drink while riding. For this reason, I am on my second valve, and am currently in need of a third. Overall, this is an AWESOME pack. Unless you want to carry your life on your back, it will not disappoint you. Just a tip... if you tuck the hose under your arm (through your arm pit), then bring it across your body to the magnet, it will be in better position for a hands-free drink.