I previously owned the Hermes and now the Singxer SU-6 (with a 9V LPS). The Hermes I had was glitchy and I couldn’t make it reliably work in my system. The Singxer does not audibly/significantly change the sound, either for the better or worse, but it has been operationally rock solid and it does allow me to use a variety of outputs. Also, its I2S output is adjustable for different pin configurations.
The SU-6 is currently on the sidelines, and I am running USB direct from my streamer into my DAC, with a Singxer UIP-1 (with Channel Islands 7V LPS) in-line to clean the USB signal. As with the SU-6, I do not hear anything particularly different with the UIP-1 in the chain, but nothing worse either. It sounds good, at least as good and maybe a bit better than with S/PDIF out of the SU-6.