The sound difference you're describing reminds me of when I had too few ferrites: there's a kind of "hyper detail" effect, but it's not obviously harsh or fatiguing. I found it quite attractive for a few days.
I suggest that, instead of a quick A-B using a few pieces of music, you use the USB connection for at least a week. My approach in comparisons is to spend a reasonable amount of time with the change before doing A-Bs. It takes longer, of course, to make decisions.
The best guide to better system setup is always to choose the system that shows the most difference amongst the pieces of music you play: maximising the differences. Allowing more of the characteristics of each recording to be more clearly differentiated from other recordings.
A good clue when doing A-B comparisons is to pick the one that sounds quieter: a more distorted sound gives the impression of being louder - a small amount of unpleasantness is perceived as being louder. I suppose it's the brain's way of raising a red flag. Distortion is, to put it simply, aggravating.
Now playing: Tuvaband - (It's Not About) Running