A comparison between Ethernet and USB

I have performed a comparison between using Ethernet UPnP and USB (direct file access, not synchronous or asynchronous USB), using my ND5 XS:

Apparent (empirical) results

1          Ethernet UPnP (via Synology Diskstation and modified Chord C-Stream cable)
Baseline sound for comparison

2          USB memory stick (Ethernet cable still connected)
More forward presentation (smaller sound stage)
More bass, but also slightly less precise, more ‘bloated’
Same amount of sonic detail

3          USB memory stick (Ethernet cable disconnected)
Same as baseline, no discernable difference (i.e. same as via Ethernet)

After result 2, result 3 surprised me, I expected to find

A          the presentation to be as per test 1 (not so forward and larger sound stage)

B          more detail

C          the increased bass of test 2, but with the precision returned

-   effect A was there, but B and C were not.

Whether other people get the same experience is an entirely different question!