Christiaan Punter at hifi-advice.com very recently did highly favorable reviews on Playback Designs MPS-X and then later on MPD-6. I have been a fan of his review style. The MPD-6 in his review had the Steam-X2 option installed. I found it very interesting that as part of the MPD-6 review he additionally tested Antipodes K50 USB and AES/EBU as well as Grimm MU1 USB to MPS-X and then PLINK to MPD-6. He is very enthusiastic on the results doing so with the K50 (original model). If you have MPS-X, I would be interested in reading your impressions of the K50, MPS-X, MPD-6 combo.