So I've now made one and decided I don't like their design enough to carry it over to the good fabric. There's really no point in copying this backpack exactly, especially since I want to sell my own patterns some day. This is one way to go about it. Another way I'm going about this is by kit-bashing several patterns together into something that's closer to my own creation. 

What I'm going to do now is to redesign the cargo pocket and make it come out with roughly the same dimensions as the model backpack.