I've been working away at my remnant quilt and the pebble quilting. I have almost a fourth of the quilt done. It's definitely slower than stippling or straight-line quilting, but it's going faster than I originally anticipated.
I had to go buy more thread! Like most kinds of dense quilting, this method uses a lot of thread. In fact, I am only taking a break right now because I ran out of bobbin thread!