Can't say for the others, but I have heard the C1 on it's own at home in my system, and it was very impressive, but after 2 hours I was bored. It didn't float my boat, was too hifi and cold for my taste. It also proved to be a bit harsh on average female vocal recordings for example on my Stax 009s. My Audio Note or AMR was fine. I have no idea why this is, possibly the USB on the C1 is not as good as Ethernet? This may not apply to all systems, and your mileage may vary.
You must try C1 + X1 it's another league.
For streaming the ethernet option is the way to go, better than USB.