Bought it as a high quality compact field recording rig with a smartphone as a recorder. The preamp quality is super, very low noise, clean and flat response. Was very surprised by the quality of DA converter along with headphone amp when using it as an audio interfcae. Didn't expect that my Sennheiser HD650 can have such sound and that it will be so different from my other interface. But somehow sound becomes so open and detailed almost like through a pair of speakers.
Also quite handy as an interface for a laptop for online conferencing with high quality audio (with schoeps ccm41 on top)
Handling this preamp in the field is not so easy though. Requires some custom made angled mini xlr cables and adapters for audio and usb c to fit it in a custom made bag. Eventually it becomes a bit more bulky than when you look just at the preamp itself. Only two knobs for setting up also takes a bit more time than usual recorders or interface.
But still so far it's probably the best I can get on the market for such compact field recording rig with high quality