I received mine a couple days ago. No problems with updating the firmware and the LED seems to reflect the various formats properly. I am using this to hopefully better the headphone out on an older iPad Mini 4 using my IE200.
Some very initial thoughts:
-Treble is a little bit rolled off giving a warmer sound. I gather this is good or bad dependent on your IEM.
-Better soundstage and separation than the iPad.
-Better resolution and timbre of midrange and vocals.
-Better low end punch and control.
-It would be great to be able to turn off the LED. It's bright, I assume wastes battery and will attract attention in public.
-It seems to do better with different streaming sources. Apple music sounds the best and then Tidal and Spotify. I'm not sure how I feel about MQA through this, it sounds somewhat diffuse.
-It seems to sound better via the USB C out on my iPad Mini 6 as compared to the Lightning out on the iPad Mini 4.
-I feel I am at the limit of what the IE200 can provide with this DAC. I may try a planar IEM next.
Considering the price I am pretty impressed. I wonder if we will see some increased competition in the dongle world because of this unit.