Great write up as the others expressed and really gets to the heart of your M3 experience. My older cars, though not M3 pedigree, deliver exactly what you describe. My VW Fox is lively, fun and with the mods over the years has made a fun autoX car too. My 1966 MGB is the same, entirely predictable and has the best steering, besides my Dad's old E30, that I've experienced as a driver. It feels alive and visceral with the noises and sensations from a car designed in the 1950s.
I'm glad you're happy with your Goldilocks. I want to get behind the wheel of an golden era BMW soon.