I demo'd Holo May and Spring KTEs with a two-box streamer made by my country's Holo distributor. I did not get to do proper A/B testing, but I heard almost none or no difference compared my Node and RME DAC. With the May, definitely a difference, but nowhere near the price difference--I left the demo feeling much much more confident about my setup as-is.
Disclosures: I have almost zero experience, zero engineering or audio knowledge, and my opinions should not be taken without salt. My setup (Node, RME, balanced Mogami interconnects, a powerstrip with Faraday cage enclosures, and a Carbon) may or may not induce cackles--they are welcome if they are wrapping for advice. And...I use ALL the tinkering features the RME provides, and I get a sound that is pretty close to what I imagine is my hearing ceiling. I use a Soren Brix-build Carbon.
I was looking at the Chord Dave and TT2 as well...until I stumbled upon the thread here about Chord Dave...