Sibilance

There are different remasters of that album and they sound different. Sometimes it's hard to tell which version is being streamed.

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. 

Vibration was mentioned earlier. Are your components isolated from your rack/furniture? Are you using any footers to decouple or drain vibration from the components?

My system suffered from harsh highs on many digital tracks, CDs and streaming. It took me awhile to find that the DAC was vibrating on it's shelf. I was using aftermarket footers but they weren't good enough to stop the vibration of the DAC. 

If you're using the Node2i's internal Dac, then I agree with buddyboy. Adding a standalone DAC will improve SQ in every way. A R2R multibit has a more forgiving presentation.