@zlone From what other owner’s have told me about the Holo Audio Serene and also from the measurements. It seems to me very similar to the Benchmark LA4. I have been told the Serene has a touch more warmth.
I can tell you that the LA4 and the CODA #8 were amazing together. I spent a year flipping back and forth between the Benchmark AHB2, Benchmark LA4, CODA #8, and CODA 07x. That is, I used them in various permutations. All combinations of the gear matched so nicely to my ears. I got rid of some of the gear because I thought it was a little to crazy to do this. I only sold the CODA #8 (reluctantly) because I wanted to buy the RAAL VM-1a headphone amp. In hindsight it was a great move.
I also owned the Schitt Freya+ for a few months and I was very happy to find it pairing nicely with my RAAL SR1a headphones and the Benchmark AHB2. I had a tough time making the AHB2 work with the RAAL SR1a, even though the SR1a designer used the AHB2 when developing it. The Freya+ was a great tone control to the bright SR1a and neutral AHB2.
Today, I am using the LA4 and AHB2 monos with the SR1a headphone (on my 2-channel) setup. I cannot believe it works because it was awful before. However, this time I am using the Musetec 005 DAC which seems to be the magic sauce that holds it together. The Musetec 005 is not good with my RAAL VM-1a headphone amp (surprising).
The Blades are a decade+ in the making for me. Either no space, no money, or new baby.