Not sure if this helps, but I'll give it a go. When using USB over a very well know and continually well reviewed Dac, I felt I had a very good system. I did however yearn for a little more, and I wondered about these split USB cables, and alternate power sources etc. My Dac was asynch and galvanically isolated with some type of extreme reclocking enabled to supposedly be the statement in USB audio. It was pretty good but I always wondered "What if?".... So i engineered my own split USB cable, after about 4 attempts and several hacked cables, I got it right... and it maybe sounded a little bit better. but splitting hairs to a degree. I then found an affordable "memory player" software for my iMac that did infact seem to let things flow better than Itunes. So there I was, all tweaked out and happy with it.
Along came DAC DAC. and the usb to spdif bridge that I mentioned above. no more spit cables, and iTunes sounds freakin fabulous. The Halide uses some implementation of Gordon Rankins Streamlength tech I believe. And Tommy may speak to the immunity of the DAC DAC input to jitter. But honestly, I am no longer craving extra devices or tweaks.
My suggestion would be to get your hands on DAC DAC and then some version of SPDIF delivery, and enjoy your music for the first time.
Tommy O's ears work well, and he somehow manages to make great audio at affordable prices!