Two different reactors.
The LN2 cooled copper magnet reactor is for experimental versions burning D-D to start. This is strictly a test reactor. The reason for LN2 cooling and Cu coils is that it is quick and not too expensive to construct. Operational costs might run as high as $2K to $3K per hour depending on electrical and LN2 requirements.
The superconducting magnet version burns pB11 from the start.