Designers of this bag knew what they were doing.
Materials, attention to detail, and easiness/joy to use it are great.

Materials. Waxed canvas is a great idea, it gives flex and this bag is more roomy than you can expect (I do not like hard/rigid bags as they typically are more complicated to load, however, this particular bag can feel slightly flimsy to some of the users). Moreover, waxed canvas ages nicely and I typically like the patina of waxed canvas. Rigid side walls provide structure and work well with a combination of waxed canvas.
SBS zippers are very smooth (I like YKK zippers more, however, particular SBS zippers work really well).

Attention to details. Zipper pulls, zipper "garages", attachment points, hook, handles, strap keepers - all these thighs are nice and useful. I was surprised that soft interior materials are used for side pockets to protect your phone, etc.

Things to improve with next iteration:
-- High visibility interior - orange or bright green interior would help to find items better.
-- A few internal mesh pockets (in the main compartment) would be really nice.
-- Bigger zipper pulls (for reference - Goruck zipper pulls are the best IMO, they use beefier paracord and shrink tubes).
-- Zipper "garages" of side pockets should be on the opposite side (currently they will collect rain water instead of preventing it).
-- Size or two bigger zippers of main compartments - would look better.
-- More comfortable top handle would be great (or similar to mid-handle at least).
-- Bigger straps would add more comfort when the bag is fully loaded.
-- I'm not a fan of rigid thermal isolation material, I believe that more flexible material similar to the one that is used in ADV Tennis bags would work better.

Despite these noted improvements - this bag is great, simple and enjoyable to use.