The extech unit has the advantage of providing a safer means to connect the voltage probes. I can work around the lack of IEC 320 connectors. I have heavy duty line cords with a 5-15 on one end and the high current IEC 320 on the other end.
Assuming the x1 port will work if I push the current up to 18 or so amps for a short time interval, I can make this unit work.