@mistercrash I have the Helios here burning in. The first batch recently arrived in North America. I have listened to it initially and it sounds great. Sort of a middle ground between Playback and Aries Cerat. It is dramatically better than the 501 in the sense that everything was smoother and more analog sounding. It helps that there are 4 DAC chips per channel as opposed to 2 in the 501/502. They also have improved the output stage. I want to listen to it after it has a chance to have some hours on it though for a final opinion.
I will my write up here and we are going to begin posting to a YouTube channel videos of the DAC.