It's been said that "you can't blame a compass for pointing north". And, when you make an inquiry to a group of audiophiles you can expect "audiophile" responses from "audiophiles". If the question were posed on a forum for oral surgeons: "What toothpaste should I buy -- Colgate or Crest?" you'd expect a strong critique of mainstream, available at Target/Walmart oral hygiene products as well as some professional recommendations of sensible alternatives. There ARE actual audio experts on this forum. And, the price of admission for that advice is reasonable. Free.
My part time "gig" after retirement involves servicing vintage audio equipment. The primary goal is to prevent good gear from going into the dumpster. We are indifferent to brand, price point, overall condition, etc. Our primary prerequisite is that the piece must have a strong emotional attachment to its owner. It cost us about $3 for each $1 we bring in. Not a great return on investment. Being there at times like when a retired eye surgeon breaks out into tears after we fire up his father's stereo that's been in storage for 50+ years, is our reward.
Vintage "stuff" brings us back to an era of authenticity, but it's more than that. For some of us, the journey from childhood to adulthood was enhanced by music and the hardware that produced the music. Some of the best of the best memories of our lifetimes involved those knobs, switches, levers, meters, dials, and fret wood grilles. While it might a stretch to call them a literal fountain of youth, our old gear certainly does return us to "feel good" moments that are unique to that equipment. Referencing, again, the service component mentioned above, I'm sure that in 90% of the cases listed above, if the owner(s) were offered 10x the value their equipment in exchange much better sounding modern gear, the answer would be a resounding "NO!"
Seeking a "rational decision" involving elements with an emotional attachment is an irrational approach in that it is impossible to place a value on the those elements.
That being said, the OP's comments about the group, in general, was a bit heavy handed. I am genuinely impressed with this group's commitment to serving others. These are the kinda guys I'd like to have as neighbors when my riding mower won't start. They'd be there to pull the plug, rebuild the carb, etc. Then, offer ME a cold one after THEY've done all the work.
As, yes, the HPM100s are pretty special.
Just a note to my A'Gon friends: Mainstream vintage gear can take on real audiophile characteristic with a little attention to parts quality and application of "newer thinking". We do this routinely and are often surprised (stunned!) with the results.