Have you found your "End-Game" speakers yet? I have. And it feels so good!!!

OP, “…Over the years, my speaker "Revolving-door" was a learning process for me…”

Was your door also revolving with respect to electronics? Since many different speakers will require very different electronics to sound their best. Or did you keep your electronics the same and swap speakers until you got a solid match?

Final speaker… no surly not but I will be keeping my JBL 4367 for a longtime. They have no real flaw and do a lot of things really well. I will happily move up the JBL line when and if I get the chance.

I have pivoted more toward my home theater (new projector/screen) since buying the JBL as I don’t read or look for other speakers. I might buy some new subs as they will be used in both systems (same room). 

I pretty happy with my Joseph Audio Perspectives.

Yes - Reference 3A de Capos. Paired with a good subwoofer and this is all Ill ever need.

Well - I may try Klipsch Cornwalls at some time...

Quad ESL's - 2 pairs , plus pair Magnepan DWM's plus isobaric sub. Had the Quads 15 years.