I have a couple of Camelbacks (one was a gift) and almost never use them, even though it's 95-105 around here most of the summer. I'll take one on a long ride when I'm not sure of a water source, but for ordinary riding, commuting and suburban stuff, I'd rather carry bottles and look for parks and 7-Elevens. I just never have gotten used to riding with a backpack. Besides, it's an excuse to stop for a minute...