This on usb cables

Most of new gear uses asynchronous USB, meaning that the timing (clock) of USB transfers and clock of internal D/A conversion are independent.  Because of that cable should not affect the sound but often it does, because it picks up noise and injects it into the DAC, affecting timing of D/A conversion (jitter=noise).  I would chose well shielded cable without power wires, if your DAC doesn't need it.  Some expensive, exotic USB cables will sound better if you believe they should - nothing wrong with it, if it helps  :)

Read: some that you believe should sound better will indeed sound better. 

No it is not.  He might believe that "some" expensive cables would sound better, but would not necessarily believe that all expensive cables would sound better.  Logic is a tricky thing.  ;)