I remember listening to a couple of 'remasters' back in the late 1990s of this and Led Zep IV and being disappointed at how they sounded no better than earlier (first gen?) CDs.
I have so many different Zeppelin remasters. You're right about removing tape hiss and tipping up the highs, that's what they did to so many rock albums. This was in the 90's before the use of high compression and The Loudness Wars.
I have excellent hearing, but also have a sensitivity to high frequencies.