I think it's fair to play the new mix some 4 to 5 dB louder (so the (lead) vocals are in the same league).
I agree, and have done some more listening at higher levels (though not comparison), which of course raises the impact factor. And I'm sure this mix can be played very loud indeed and still sound good. But in the end, the mix is still the mix, and my ears don't want to hear KE's Hammond sounding so subdued compared to other instruments, during the first minute or two of Tarkus.