One last fan-boy Zu plug. The Soul (standard) was just released with preorder pricing at $1500. From their description it sounds like it will offer a lot of what the Superfly does.
What is the difference in sound beween Soul and Soul Superfly?
Both are great hi-fi products. Both produce the famous Zu sound (dynamically dense, big, with excellent timing, amazing stereophonic realism, and coherent and compelling top to bottom / loud to soft authentic fidelity. Soul Superfly just does more, and better.... Areas that are noticed most include the midbass and up detail, things are a bit more relaxed and at the same time are more clear and distinct with the Superfly Edition. Treble is really integrated and tone rich with the Mundorf Silver/Oil cap and B3 silver alloy cable used in Superfly, and the presence and magic of good stereophonic recordings is breathtakingly convincing.
Which one is best? Soul Superfly. If your budget allows, and your main focus is for awesome traditional stereo hi-fi then run with Soul Superfly. If you still have a long list of music you must own than save some cash and run with Soul and be satisfied.