I just got the Z1 about 2 hours ago. If you're a FLAC guy like me,..this one is a no brainer. Get this now!! It sounds amazing. I haven't even rolled the op-amps (I have a Burson in the wings) whatever is in there now, sounds great. Great vocals and soundstage. Can drive my HD650 Senns no problem and sounds really good (unlike the Walnut which doesn't). I don't know about the new Walnut, but the Z1 sounds better than the nut I have (soldered op amp). Obsolete to me now (after only a week haha, oh well). My mojitos never sounded so good. It's a tiny bit smaller than the nut and lighter too.