Shouldn’t be that surprising, it has at least one distortion circuit similar to Analog Heat, on top of that are 4 analog voices and a CPU which has to do a lot more than the one in AH.
Those 4 analog voices can also be sent over USB audio if I’m not mistaken, which means there’s an extra A/D converter in there or a different one with more channels.
And the analog voices are probably always on, most synths tune their analog voices on startup.
All this in the same size enclosure.