The most important thing to me is the sound quality of the speakers. They set the stage for what you are going to hear. That is it, no consideration of efficiency. Then I find the proper amplification to support them.
After a love affair with electrostatic and ribbon speakers for decades… which I supported with 150+ pound, massive high powered amps. I realized I really wanted natural / musical sounding system. So I found Sonus Faber speakers, which are mostly 90db efficient and them I found the best sounding amp to support them… so the wpc went from 350 to 70.