I just recently purchased a mountainsmith one, and, actually like it for the warmer weather. Although, I did pick up a pair of suspenders for them, as it annoys me when it slides down my butt. I keep a canteen in one side, a FAK in the other, a journal, small survival kit, AMK bivvy bag,rain jacket, and some snacks inside it. I'll carry a fleece on the outside bungees, if its cold enough. I can also stuff a pair of mittens & wool hat in mine. I like not having a sweaty back at the end of the day.