I have been comparing some of my master tape copies and original LP releases to the reissues I own. I have written about my (limited) experience with Analogphonic here:
https://www.psaudio.com/blogs/copper/the-joys-of-monophonic-recordings-part-one
And about some EMI tape releases here:
https://www.psaudio.com/blogs/copper/tape-versus-vinyl
You can read about the Analogphonic mono Milstein releases, but enough to say that I never bought from them again.
Another recording I compared extensively is the Solti Decca Beethoven 9th. I have the original Jubilee box set, the Speaker's Corner reissue and the MFSL from 1981. I also have a copy of the Decca production master. The recording was panned by most critics for the sound, and I guess with Solti having must taken up his post in Chicago, the Decca engineers were still trying to figure out the venue and the band. I must say though that the tape sounds hugely better than any of the three LP releases. The original Decca box set was the weakest, almost unlistenable with compressed, muddy sound. The Speakers Corner was better, with more clarity, but it has a hardness to the sound and dynamics were still compressed. The MFSL was the best of the three, but still unsatisfactory in my opinion. I understand the difficulty in transferring large choruses onto vinyl. Much easier just to compress the dynamics then to try repeatedly to get a clean cut.
On the other hand, I have the production master of the Solti Beethoven 3rd . The one with the VPO and the lion on the cover. It is also a difficult LP to cut, given the length of the movements (the second movement was cut onto both sides). The tape is absolutely fabulous, and so is my original wide band ED2 SXL release. In fact, this LP sounds closer to its tape than any of the three Beethoven 9th LP versions to theirs. And that record was cut in the early 1960s. I think at the end, it is a matter of how much care and effort was spent on the mastering.
Another interesting comparison is with my set of tapes made from the studio masters of Elite Recordings, including the VOX Ravel box set which was the subject of an early AP reissue (
https://www.psaudio.com/blogs/copper/a-look-at-ravel-s-works-for-orchestra). I have also compared a production master of the RCA Royal Ballet Gala Performance with my Classic Records reissue. I can write about it here if anyone is interested.