Then it's hard to imagine two people more at the opposite ends of audio than you and me. If you want a preamp that does not at all change the amp sound, and you seem not to need the gain, then why not just opt for a passive preamp?
It's not what a preamp adds, it's what it lets the amp reveal. The purpose of a better preamp, at least as I see it, is to make the amp sound better that it would with another preamp ahead of it. By better I mean to make what comes out of the amp sound more like live, unamplified, music. A fine piano or violin played well should sound warm and smooth. Same for a good voice. Of course some musicians can make ugly sounds and a good system should reveal that too. A better preamp, to me, is one that lets what's on the media come through the amp sounding more like the live event at the original taping. A preamp's function, beyond switching, volume and remote, is not all that well understood.
I don't know anything about the Holo, but I have experienced Benchmark products over the years, including DAC and preamp. They have a house sound, and have always had a house sound, and to me that sound is just clean, dull and electric. No wonder, with their switchmode power supplies, chip op amps and heavy feedback. They always measure very well and I know lots of critics and lots of people say they love them. Not me.
Just one opinion here, no more valuable than your own.