I just received this device, along with a FiIO X5 to replace my now discontinued iPod classic.
 
At first I liked this device - smaller, lighter than the FiIO, although only 1 slot.
 
Shipped without any user guide, however.
 
I formatted my 128 G SD card and inserted it, connected it to my mac.
 
I used doubleTwist software (which I had successfully used with the FiIO, and let it sync overnight.
 
I came back and and the device seems to think I had no music. I plugged the USB cable back in, and the files where definitely on the card.
 
Tried factory reset, tried formatting as exFAT.
 
I went to their website - www. ibasso.com - and it is a mess. Every link leads you to their download area. 
 
I have the latest firmware v2.1
 
I emailed their support but haven't heard back.
 
So, the device can only find files on the built in storage.
 
So, as a "high end" player, this device is useless.
 
Until the hardware companies start making software at least a little better, acceptance of these products will be low.
 
The FiIO X5 was difficult enough to set up - took a while to locate the doubleTwist software. Copying files from the Mac to the DOS formats using the Finder
creates little .trackname files so that every album looks like it has two copies of each song.
 
I will try to assemble the packaging for a return.
 
Rick