Some insights from Roger Nichols who recorded most of Steely Dan records about transients that already disapear from analog mastertapes with in a few houres. So what about the quality of analog masters (guess the majority) that are already loosing transients with in a few hours. I would say enjoy the music despite lose of transients still enjoyable enough i guess but don't expect or claim it is the original sound the engineers heard when it was made. I have the impression that MQA claims or suggest that.
I bet my current Aja Cd from1989 wil contain more transients than a MQA file made of the same master a few months/ years back
Roger Nichols: Yes, and it’s mostly because when I record something on a digital machine..um, you know, and I play it back ten years from now it will sound exatly the same. So if there is some little artifact because it’s digital, it’s a majorable (sic) artifact, and it’s going to be the same artifact ten years from now. If I record something on Analog tape and it doesn’t matter whether I’m do using Dolby SR, Dolby A or DBX or no noise reduction or whatever it is, if you record something on a piece of analog tape and play it back later the same day, the same program is not on the tape. And there’s nothing so far that anybody’d been able to do about that, you know, like those little magnetic particles are made to be able to wander around and they do so by themselves while the tape is just sitting there. I’ve made DAT copies when I’m cutting tracks, and then have an automation snap shot of the mix and then later that evening put the tape back on, play it back, compare it with the Dat, and there’s already starting to be a difference. And by the time a week or two weeks go by and it’s time to mix, a lot of the transients have started to disappear. If you use this as a tool, some people like what this does, and it sort of helps to mix all their music together, that’s fine, but, you know, you can’t say that Analog tape with Dolby SR is as good as Digital. It might be as quiet, and but it’s not going to retain the signal, you know, as long as Digital tape. So that’s my biggest worry about Analog tape.
http://pieralessandri.com/ROGER-NICHOLS-interview