Another big mover was that the new FM's had few, if any, commercials. The only new format I remember in SFO was AOR and that wasn't a very popular format outside Haight-Ashbury and Berkeley.
The new formats may have had few commercials for the first year, but they quickly monetized the newly found ratings.
KMPX was the first progressive station in San Francisco going on in mid-1967. It was decimated by a strike the next year, and Metromedia launched KSAN, which was an immediate commercial success in the same way that their stations like KMET, WMMS and WNEW-FM were.
"AOR" did not exist as a format until the advent of the Superstars tight list format towards the middle of the 70's under consultant Lee Abrams. The Superstars formatted stations were enormously successful and generally sold out in those days. They got astonishing ratings, often beating the leading Beautiful Music FM through the rest of the 70's.
I just did. If I wanted HD in my house I had to buy an HD radio.
Check the sales rank of the Insignia; it is below 11,000 in electronics. It looks like your purchase was probably the only one in a week or so and it only has 93 total revues despite being a relatively "old" item.