Hmmmm....okay, I tried Steve's hearthkit idea just now. The pizza dough was *really* delicious, and certainly had a much better texture than I've been able to achieve previously. It was chewy, soft, just airy enough...yet had a somewhat crisp, leathery bottom. Very tasty too!
However, I don't know how much of it I can attribute to the hearthkit concept. I also used a metal cookie tin to store the dough in the refrigerator overnight (I used to simply store the dough in plastic grocery bags tied shut). The dough seemed to be very happy in the metal tin (it rose smoothly and seemed more pliable than usual), so maybe that had something to do with it. Also, I wasn't able to achieve the "charring" effect that Steve did. I wanted to leave the pizza in longer, but the cheese was starting to burn.
Anyway, it was an interesting experiment. I have another ball of dough, from the same "mother dough", stored in the metal tin, ready to go for tomorrow night--I think I'll try doing the pizza without the hearthkit and see if it makes any difference.