My M8 was sent on Wednesday and scheduled for delivery Monday, but the Fedex man came early today! First impressions...
The M8 is very,very well built. The curved sides make it quite nice to hold and carry around.
I've mainly been using it with an iPod Touch 3rd gen as the source.. The M8 really goes well with an iPod Touch. The thinness of the Touch makes it seem more like a thick DAP with a screen than a two-piece rig. I am using a short 3cm 30-pin to USB cable that is a little shorter than the Centrance supplied cable. With this cable, the M8 with Touch fits nicely inside a CaseLogic hard drive case I have without having to disconnect the two.
I also briefly tried it with an iPhone 4 on iOS7 two ways -- the normal iDevice way to the USB A port on the M8, and with a 30-pin CCK connected to the computer USB B port on the M8. Both connection methods work, and both produce audio from 24/96 files, although I cannot confirm whether the M8 is running native or resampling, or whether the iPhone is feeding it 24/96 in the iDevice mode. I do know that the HRT microStreamer decodes the signal at 96kHz (as it has a status light to show it) using the CCK with the app I am using. I assume that the M8 does the same thing with the CCK -- i.e. 96kHz playback when connected by the USB B port and with a specialized app.
On the sound: The M8 driving the W1000X puts a smile on my face. It think my hunt for a better headphone may be slowed a bit with the M8. I need more time to listen, so I will try it more tomorrow with my T50RP w/Alpha Pads, a much harder to drive headphone, as well as my older Senn HD580.