One possible solution to giving an amp some 'figure of merit' based on reactive loads is to Standardize such a load and let amps fight it out.
Also, I've seen an amp tested the following ways.
Into a resistive load....Try it at 4, 8 and 16 ohms.
Into a +45degree reactive load at the various resistances
Into a -45degree reactive load at the various resistances.
Afte the above, you can draw a very nice plot....would be a 3-d plot and visually tell how an amp performs into real world loads at a glance.
However, for easy of testing, the 'standard' speaker load makes more sense.
It could be reproduced anywhere at any time by any competent tech and the results would compare with all others using the same method.
But, that's just my take.
Also, I've seen an amp tested the following ways.
Into a resistive load....Try it at 4, 8 and 16 ohms.
Into a +45degree reactive load at the various resistances
Into a -45degree reactive load at the various resistances.
Afte the above, you can draw a very nice plot....would be a 3-d plot and visually tell how an amp performs into real world loads at a glance.
However, for easy of testing, the 'standard' speaker load makes more sense.
It could be reproduced anywhere at any time by any competent tech and the results would compare with all others using the same method.
But, that's just my take.