Why no interest in reel to reel if you're looking for the ultimate sound?

I kind of foolishly fancied that Abbey Road would have used something like a top quality Studer (certainly in the back half of the 60s) but no. Apparently they used a British design instead - the BTR3 (British Tape Recorder 3) to record most of their seminal albums.

https://en.m.wikipedia.org/wiki/British_Tape_Recorder

I also recall a quaint story I heard about when Sinatra came to record in London in the early 60s (I think it must have been the 1962 Sinatra Sings Great Songs From Great Britain/ CTS Studios). 

Legend has it that he was so unimpressed with the technology available that he had an Ampex tape deck and operator specially flown over for the occasion!

Perhaps some fan of Ol Blue Eyes can fill in the details. In any case these mastertapes are still the best source of this priceless music that we have.

To have a first or even second generation copy of a favourite album...

Cassettes can be pricey, too. The 100 most expensive cassettes are....

https://blog.discogs.com/en/top-100-most-expensive-cassettes/

"Legend has it that he was so unimpressed with the technology available that he had an Ampex tape deck and operator specially flown over for the occasion!"

Nebraska by Bruce Springsteen comes to mind. LP from 2014 sounds just fine, really fine.

"Cassettes can be pricey, too. The 100 most expensive cassettes are...."

More ridiculous the title, more likely to be on the list.

Much of Nebraska was recorded on the Tascam Cassette Porta Studio. ( I owned one ) One of the reasons I advocate serious audiophiles make live music recordings is to discern merits and - of format, mixer, cable, microphone, microphone preamp, etc....

of course Nebraska perfectly suited to the Tascam