Now I'm gonna have to go read it.
Sorry I read page 47 instead of 30! However here is an important excerpt from it
First, it used finer frequency resolution measurements than the Consumer's Union model (1/20-octave versus 1/3-octave). Second, the new model considered several different target functions other than the "flat" sound-power target preferred by the Consumer's Union model (Consumer's Union, 1973). The new model considered the slope, the smoothness, and the average narrowband deviations within the sound-power curve as possible criteria for predicting the perceived sound quality of the loudspeaker.
As I pointed out both methods were anechoic miking on and off axis. However the harman method includes more data points and allows additional modeling criteria. In effect its a refinement on the original testing model.
Like weather forecasting 30 years of expirience and additional data points make a noticeable increase in model prediction. It didnt make the previous one wrong just makes the new one better. When introduced the CR model was state of the art.