I listened to a number of CD/4HD comparisons and came away a believer. The 4HD sounded "less digital," cleaner, and just better than the original CDs. The difference in clarity was the single most impressive improvement hard drive replay offered.
We even compared SACDs to CDs (of the same title) ripped to the 4HD. Again in this test, the 4HD's clarity trumped SACD's. I love the fact that the 4HD, unlike most music servers, doesn't need to be hooked up to a computer. It's just a great sounding hi-fi component that can store up to 20,000 tracks at 24-bit resolution.