I have that Gustin bag. Secured one in the first run production. Entirely happy with the bag. I don't see any obvious fail points. It is well constructed and the waxed duck canvas is softening up nicely. The zippers are especially good. My only criticism would be the lack of any internal pockets. Have never owned a Filson so I cannot make a direct comparison but I don't see the above attachment point discussed as a cause for concern.
8/6/14 at 9:02pm