I still haven’t ascertained whether FireWire 400 breaks under High Sierra, or whether the USB/FireWire 400 card I had installed on the machine is somehow faulty—its USB ports work—but a little $10 dongle that adapts FW400 to 800, connected to the built-in FW800 port on Big Cheese, has restored the iSight to functionality. Woo and yay for small victories. For the rest, the big brute has performed more than satisfactorily thus far, and if I reach the end of October without Mudbrick Technologies yanking my chain with a subscription demand, I will feel very gratified indeed. SSD + 16x former RAM = Ahhhh...

cordially,