The Cordura is an excellent fabric and might in fact outlast the tin cloth in the Filson products. It will not, however, "stand at attention" for you like the tin cloth will. The tin cloth is semi-rigid and will stand tall (like saddle leather), and that can make for additional utility.
Cordura is super durable and very water repellent; an excellent product.
For a small bag I prefer the tin cloth for its shape holding ability.