I've been using a Waterdance for several years and love it. It is extremely durable (more so than the WJ IMO). It holds plenty of gear -- 4 fly boxes, the usual accessories, a small camera, a water bottle, and even a light lunch or packable rain jacket. It does come with a strap so you can use it like a sling pack. I do that on occasion, but my back does much better when I use the hip belt to get the weight on my hips rather than my shoulder and upper back.