I don't usually carry much with me, I have a Camelbak Viper that i love, it holds alot of water and I clip my binos into the D rings and I can go all day. There is a little room for stuff in the zipper pouch as well. Someday I may upgrade to a Camelbak with a little more pouch space, but I love the one I have. I've never used a serious pack, I don't usually go far enough, alot of guys here do though.