I ended up having a listen to a friend's X16 a few days ago. The sound quality out of this DAC hits well above it's price point. I currently own an SMSL M300 MK2 (AKM 4497 DAC chip used). I ended up doing a direct comparison between my M300 MK2 and his X16. It is interesting that the X16 does not have any of the usual SABRE glare in the mid treble present. The unit is very detailed, clean, and airy, but without any of the usual piercing harshness or brightness present. I was surprised, as I expected to hear the usual 7-9kHz brightness that is almost always present in SABRE based units. Comparing the X16 with my M300 MK2, it was obvious that the Gustard is a full step up in sound quality. Bass tightness, vocal accuracy, soundstage, imaging, layering, transparency, detail retrieval, and treble extension were all superior on the X16. This Gustard DAC has a very quick and clean response across the entire frequency range that I did not expect to her at it's price level. It is also extremely neutral in it's sound signature, which I really like. The M300 MK2 is also known for being quite neutral. With having a one hour or so listen to the X16, it sounds like the perfect upgrade from my current DAC. Has anyone here done a direct comparison between the SMSL SU-9 and the X16 ? I have never heard the SU-9. Both of these units are around the same price point, so I am quite interested if anyone has heard both in action.