Yes, I was on top of that as soon as he came out with it, grabbing all the info I could, patents, etc., and modeling the result. There is an interesting tradeoff between performance and complexity. By performance, I mean the little humps in the log plots of gain-vs-voltage. As for the patent issue, I'm free to design with the idea for our internal use, as anyone else is, but the idea's complexity and matching requirements make that impractical (it's too bad there isn't an analog equivalent of cPLD or FPGA chips). You don't have that problem, but your only practical use for it is commercial. So all either of us can do is admire the idea on paper.