>>246873I have the non-waterproof version of this (pic related). Great item. I use it day-to-day in the city. I take it with me while travelling as a secondary bag. I use it for day hikes. With my normal edc it is so light that I think I've left it behind by accident. When mine gives out I am going to get the waterproof version.
>>246868A water bottle pocket on the outside would be nice. I put my water bottle inside along with my other gear. Make sure to use a bottle that won't twist open while hiking.
>>246884These kind of bags are so small that the ergonomics don't really matter. You will only be dealing with very light loads. The only thing to watch for is that the straps are slippery. I use a small clip to hold the straps together like a sternum strap.