Pottery Barn: a necessary evil. We don't mean to be snobby, but we have been dissappointed on many occasions by Pottery Barn, so we now shop there with extreme care. In general, we find the quality of the furniture is not the best, and that many items don't last long or look too good after 12 months. HOWEVER, we are a big fan of a few things, including their curtains.
If you want the light airy feeling of cotton curtains, either over a window or over a closet where doors have been removed, the Sailcloth Drape is an excellent, affordable choice and super easy to buy either at a PB store or via the web. For $20 - $30, you just aren't going to do any better by looking hard, and they are always in stock.
We have recently been buying the Everydaysuede, the Dupioni Silk and the Carlisle Drape (current favorite), which are much more expensive, but still good prices for those fabrics. MGR
I think good ol' PB has some better Buyers in their window treatment departments these days, as you're right about the products you cite. They seem to be offering much more cohesive and interesting layering options, and have even added (I believe via catalog and Internet only) some wider-than-standard panels that work well for the lucky few with expansive openings. Windows, that is.
The PB Everydaysuede my personal fave.
But the PB hardware is all a little "ye olde" and ornate...so for those with a more modern bent, I'd get the hanging hardware from West Elm.
Restoration Hardware also has some great options... velvets, silks and a great brushed twill that can go formal (can pass for velvet) or casual depending on the room.