The public is terribly uneducated about clays. Most won't even know what white stoneware is
This is what I was thinking, which makes me surprised to hear Mark say he can't make a living in stoneware because his customers are informed enough to have a preference for porcelain.
As I said in the original post, I can tell the difference, most of us here can tell the difference, and some discerning customers can tell the difference... but in the art fair crowd, the average Joe doesn't know white stoneware from porcelain, and wouldn't prefer one over the other, everything else being equal.
Mark C, I wonder what your customer base looks like. Lots of repeat clients who are well-informed about pottery? Do you live/sell in an area where the average Joe knows more about pottery than most other areas? I've mostly thought of porcelain as an "art" medium (sculpture, decorative vases, etc) and didn't realize that potters used it to make functional ware until relatively recently... and even then I didn't know there were advantages to porcelain in functional work until you listed them here. (I knew porcelain fired "hard" but it didn't occur to me that it could make more durable functional ware than stoneware.)
Still not enough to sway me at this point... I can't afford to play with porcelain when I'm still in the "throw 100 cylinders as practice for making identical pieces" stage. It's enough work reclaiming stoneware scrap.
I love the look of porcelain, and in stoneware I prefer a buff or cream clay... I'm not fond of "brown" stoneware for the most part. There are a few styles where I like brown or heavily speckled clay, but they're not styles I want to work in at this stage. (I met someone at the local community studio that's into reproducing medieval forms... I might get involved with his crowd, and then I'd certainly be giving up my B-Mix 5 for something a bit more on the brown side for that kind of work. He's headed to a workshop where a medievalist group is going to dig and process clay using only tools available from a medieval time period. Sounds like fun.)