Hey Allan,
No insights on the preamps, unfortunately, but just curious what do you use as a source for your listening?
To share my angle - I'm streaming only, Qobuz and local, and got hinted by my trusted dealer that probably the smarter path for me is to go down the streaming DAC route, rather than trying to pair/match two separate components. And I feel he's more than right, that allows me to find a component that is already well integrated, rather than trying to combine a source that works well with the DAC. It doesn't necessarily solve your preamp dilemma, but it might change the sonic characteristic where the highs wouldn't be so grating for you...
OTOH, I'm also curious about these two preamps comparison, mainly because I'm also considering the active speakers option, so a pre- would be needed, if for nothing more, for getting an output to the REL subwoofer. And, Nuprime is definitely on the list for that