Gee... a 1975 reissue is sounding thin and disgusting and you are blaming it on digital recording? Digital really didn't go commercial until the Soundstream recorder was released in '77, and digital was almost exclusively used for classical recordings from folks like Telarc and Denon. These were used for making LPs until the CD was released in 82.
As someone who has 1) original 3 disc album Woodstock release, 2) cassette version 3) VHS movie 4) CD release 5) 2 DVD releases, I can honestly say that the cassette version is the absolute lowest quality sound of them all. Its far from "gorgeous". I only bought a few original cassettes because they always sounded so much worse that the albums. It was better to buy a good cassette recorder and some hi bias cassettes and dub them down. Commercial cassette releases were one notch above the 8-track releases, although a good 8 track potentially could best the cassette on the top end due to running at double the tape speed. They were best relegated to the dashboard of your GTO or Camaro where quality didn't really matter.