It's pretty great, been using it in military training, both in sand, mud as well as snow. Material quality and zippers are good, long cords make it easy to grab with a glove, rubber bottom holds it in place in a vehicle even on uneven terrain. I really like the top storage compartment, I carry cables, flashlights, drone remote, extra batteries etc in it.
But for a newer version, I'd ditch the ventilation flaps, include a strong mesh inner layer that can be zippered up and open, and if open, you could roll the fabric up much like you do with a commercial tent door/window. Add a wire in it if you want to shape it similar to a flap. The flaps might be better in rain to guide raindrops, but they are using velcro, which makes noise in a tactical setting and probably is the component to have the shortest life span. Zippers are fairly quiet.
Would also probably try to use the handles to attatch a shoulderstrap to be able to carry it on your back if you need to relocate fast. The current version of the bag is okay for carrying, but the material excess prevents a good grip.
I mean if you already have two good handles, why not use it for a shoulder strap or to be able to attatch strong hooks to it, might be necessary to attatch it to a zipline or for medical personel on the side of the emergency ambulance trolley/litter, hanging from a pole. In that case, the flaps on the side will be obstructed from opening fully, that's why I'd prefer mesh+zipper combo.

Currently it's a good bag, good functionality but lacks versitality. A small compact powerful unit packed in 12kg can be a good unit for plenty of operators in several important public service fields, both in field use as well as just attatching it to the upper bunk bed rail to have power, usually outlets are much lower and with great handles and hooks, that 12 kilos is not something you'd have to be vary of dropping.

Plus if the shoulder strap is adjustable and strong, you could use it with the handles to attatch it to a ATV, due to other gear, side flaps might be a bad idea again.

Things to consider, military needs power in remote locations and generators are noisy. If you can provide a good bag for transport and quiet fans for the newer delta series products, you'll soon have an even better bestseller. So do the medical, police and other operators, but their hands have to be free. They might already have a backback on so a shoulder strap would be excellent + you can use the strap through the handles to form the hooks, so no seperate hooks are necessary, the strap can be quite versitile with the design of the delta products.