The controller sensor on the Kryotech SuperG2 unit is measuring the return line temperature about half an inch above the evaporator and I believe it also to be more accurate and optimal location for monitoring as well compared to the Mach I.
I agree, but on the modded prommies the slightly higher temperature on the suction line near the evaporator may still be too cold for accurate sensing. On the other hand, optimum charge may not bring enough cooling back to swing the temperatures for control purposes, if sensing near the compressor. Some experimentation would be in order.