Eastern Electric DAC USB input vs asynchronous

I was wondering what some of your opinions are about if it is worth getting an asychronous USB/SPIDF converter instead of using the stock USB (synchronous) input. Currently looking into:

1. M2tech hiface
2. halide bridge
3. the new wavelength usb/spdf

I'm not using any high resolution files, so the fact that the EE only does 16/44 is fine with me, I was just wondering if the mere fact that these converters are asynchronous will be an improvement over the stock USB sound. Has anyone done the comparison?
Yes, I have. Using the M2Tech Hiface vs the stock USB there is a difference. It is not night and day but I hear a clearer separation of instruments, more life-like tone of the instruments and voices, and it will pass through 192K if you have any high resolution downloads. I recommend it, especially for the money. It has had some bad press lately with people complaining it wouldn't work with their DACs, etc. It has never failed to work for me. At this cost, it is a no-brainer for me. I have used both the coax and the BNC connection and to me they are identical.
has anyone else tried the hiface, or any other asynchronous inputs?