I cannot argue with the points made for these types of devices (Camelback et. al.). They make sense for a lot of reasons. But, there is one good reason I don't own one and don't see myself owning one anytime soon. They look seriously uncool. Sure, that may be vain, but it's honesty. Unlike a lot of folks, I don't have trouble staying hydrated and I don't find lukewarm water particularly unpleasant. I'm never in such a hurry that I mind stopping to refill a bottle or two. I've no interest in sweat rash on my back, either.