Product Review (submitted on March 30, 2014):
I got this in waxed canvas, which so far (even in rainy Portland) has stood up very well, and does in fact keep the wet out. I've taken it on several short trips - even though the bag looks quite small, with efficient packing techniques, you can get a lot into it. It's comfortable enough, given the weight of what you could theoretically get into it, and a bit of strap adjustment does the trick to keep them from biting.
Overall, very satisfied so far. We'll see how it holds up for extended travel, hopefully soon.