Your question was a great one, Critterg. Most everybody loves hypertufa once they get involved in it.
And right about the 'feet'.
I made a couple a few years ago and painted the 'buttermilk - moss' mix on them, then placed them mostly in the shade. The moss grew on them, covered them in fact, and I gave them to a friend who'd just built a new home. She had lots of trees and wanted some fast shady landscaping. They are still there and I haven't made any since. You've made me want to make more.