Hello Ian
I think it's a step in the right direction. The last interface we all have to deal with, and in many cases live with, is what actually happens in our listening rooms. No amount of anechoic or quasi anechoic is going to predict what's going to happen there.
That will never change. Not going to address DSP based systems that can ping the room and adjust accordingly. Sticking to passive systems or actives without adjustable DSP.
Spinorama allows us to get an accurate DI curve. I think the DI curve is important WRT predictability of room interaction but it can't directly address where the room dominates.
It's a mixed bag.
Rob