[William Sommerwerck]

I've always wondered what might have happened if Norelco's
engineers had realized the potential of the format during the
design stage. They might have made different design decisions
that could have extended the life of the format in the marketplace.

That's not likely. The limitations of cassette are those created by short
wavelengths and thin coatings. Nakamichi, et al, pushed the format to its
practical limit.

If you want a better understanding of just what was achieved, you should a
Nakamichi two-speed deck and make half-speed recordings on metal and
premium-iron-oxide tape. This throws into relief everything that's wrong
with slow-speed recording, but isn't readily audible at "full" speed with
most program material.