Ok, the resin component of Cokin filters: If this is like the plastics used in eyeglasses(what is the Brit word for those things? LOL), then optical properties are fine. I suspect that optical properties of Cokin are fine, since such would not sell otherwise. ? Just how delicate are these filters? The mounts and accessories seem reasonable in price. Other brands are out there with apparently similar systems. Do you recommend a system rather than a brand? Hummmm...IM is ok for that answer. As for gradient filters, is there one that might be the most useful to start? I suspect in my work the gradient(gray?) would be best. I show my ignorance here. Peerhaps Zacko and all of us may benefit from the experience of others. Great thread, Zacko, btw.