"I first bought this very recording on vinyl in the 60's as a London recording. It's one of my favorite operas. A few years ago I bought the Treigle-Domingo-Caballe (EMI) version on CD and was very disappointed. I preferred the CD copies I made of my old vinyl recording. I just recently found this Siepi-Del Monaco-Tebaldi version on Amazon.com and bought it.
First, the orchestral and choral music on this version is much clearer than on the EMI version, which I think is remarkable since it was recorded in 1959, as opposed to 1976. Cesare Siepi is a powerful Mefistoffle, making Norman Treigle sound like a wimp. I don't think there is any soprano who can match Renata Tebaldi for expressing emotion; the prison scene in the third act brings tears to my eyes. And Mario Del Monaco is just as good, if not better, than Placido Domingo.
I am glad I found this. The only draw back is that all the documentation is in French. The libretto is in the original Italian, with a French translation. If you don't know the story, or Italian or French, this may be a problem."