Op,
I have found that with the exception of the very grossest measures like wpc (that is also doubling into lower impedance) measurements are largely meaningless. I mean seriously. I do not look at them. Waste of time.
Early on in my pursuit of the high end I was fooled repeatedly by looking at them. Honestly, in main stream high end the best correlation with sound quality is price and weight (taking into account the intended sound quality type… like detailed with lots of slam, musical / natural… etc).