Mapman--what you state is certainly the case with pop recordings, which are compressed so they will sound good on the radio. Most classical labels have less compression issues, unless you listen to them on your radio, in which case the radio station compresses the recording for you. Telarc is probably the modern label most akin to the spirit of the Mercuries in terms of trying to get the dynamics of a performance on tape uncompressed, but I tend to agree with Shadorne that most other companies' recordings sound dynamically compressed compared to the Mercuries. This is particularly true when comparing vinyl pressings; that was a hallmark of the Mercury label.
By the way, despite the theoretical advantages of the digital recording medium in terms of dynamic range over analog, for some reason the most dynamic recordings in my collection are the vinyl versions. Comparing the Classic Records re-issue of the Mercury Firebird against even the SACD of the same recording, the vinyl just seems to be more natural, vibrant and have more dynamic punch than the SACD or CD--more of a "jump factor", as we used to call it. Not sure why, but it just seems that way to me, and I think also to a lot of others.
By the way, despite the theoretical advantages of the digital recording medium in terms of dynamic range over analog, for some reason the most dynamic recordings in my collection are the vinyl versions. Comparing the Classic Records re-issue of the Mercury Firebird against even the SACD of the same recording, the vinyl just seems to be more natural, vibrant and have more dynamic punch than the SACD or CD--more of a "jump factor", as we used to call it. Not sure why, but it just seems that way to me, and I think also to a lot of others.