To be honest, when I think of "classic" speakers, Pioneer doesn't even come up in my brain. I think of AR, KLH, ADVENT, JBL, POLK, EPI and a few others. These American companies had the vast majority of the market share during their heyday. At one time, I heard that AR owned almost the complete market.
I've never heard the Pioneer HPM 100, and I'm not saying they are not any good. But Japanese speakers simply were not the first word in speakers of the time, and they still aren't, IMO.
Hard to beat the JBL L100.....
'ner