Got mine today and I can easily (for me) say it's better than S1 and Sparrow. To me it outclasses the S1 on pretty much everything (no eq) and sounds more precise and less digital more organic/natural than Sparrow. In fact it's better than most daps I've tried in pure sound quality. It's not going to drive full size headphones as well as a powerful dap but, I'm a iem guy anyways because I can't tolerate headphones on my ears.
Sound impressions- very full sounding a touch of analog but very precise and detailed. Very natural sounding tonality. A nice 3d ish stage presentation with excellent imaging. Mids are really lush and defined but nothing is lacking. I'm really impressed. It's a very high end sounding device.
Warmish neutral maybe. Hard to accurately describe and you probably have different iems than I do. But I'm loving what I hear.
The settings are just the same as out of the box. High gain, tone 2, fast roll off volume around 59. I've used ie800, hiby beans, akt8ieii, and meze classics 99. All sound great, so far with every genre. Tia's will be back soon to try, and I've got rose mini pro 3's coming- I like small iems. Oh, btw it even worked great with tiny fiio m5 ha ha
of course I'm sure it will kill battery on that tiny thing fast.
Also build quality is excellent and even the included cable fits tight!