Just a short note from a new user of the VxV. I am relatively new to iems, though I have been a 2-channel person for decades, so I know what I am looking for in terms of sound.
I had the Thieaudio Monarch before this. My dap is the DX300 and I found the Monarch unlistenable after some time. I suppose I have sensitive ears, because the Monarchs sounded harsh and frankly unpleasant after about half an hour of use. I have only read about a few other people who experienced them in this way, so I assume it is because of a particular sensitivity on my part, because the DX300 is not harsh at all and won't be the reason the Monarch's sounded so unpleasant.
Now I have the VxV and listening is a complete pleasure. I tried the 64 Audio u6t for a few weeks and found those a little more refined than the VxV in the trebble but darker and with a somewhat bloated bass. I could have lived with the u6ts but the VxV sound more balanced to me, almost as subtle, and with a bass that is better defined.
I listen some three to four hours a day, mostly to world music and classical, and the VxVs work for both, in that they have plenty of detail but always also convey the emotion and never cause listening fatigue.
Frankly, it has been quite an eye-opener to read about all the praise the Monarch gets, because to my ears there is simply no contest between them. I wonder if it is because of the ATOM system taking some of the pressure out of the listening, or whether it is the tubeless BAs that suit my listening style. I am not questioning the Monarchs sound brilliant to others, but it has made me realize how different we experience iems.
When I listen to music, I want to be listening to the artist and not to the iem. Quite a few reviewers mentioned they were being drawn into the music rather than focus on the iem. I really enjoy reading people's descriptions of what the different iems sound like and understand that they would have different iems for different types of music and enjoy savouring their differences. But for someone like me, who cannot afford multiple iems and just wants to connect with the music, the VxVs are absolutely brilliant.