At last, a post to which I can contribute. I have a lot of expirence with both styles of container through adventure travel guiding. The advantage of the Aqua-Pak design is that with the valve stowed, the conatiners may be neatly stacked. The design of the Water JUG doesn't allow stacking. The valve on the Aqua-Pak also seems to be a bit more rugged. One advantage of the Water JUG is that it is clear so the fluid level is easily determined. Neither container is particulalry rugged and will end up with dented corners and scratches but they do the job and hold potable liquids. There is also a 7-gallon Aqua-Pak that I've used as well. Hope this helps.