Ideal USB cable length, streamer to DAC?

Someone on another forum whose name shall not be mentioned here tested a bunch and found the ideal length was the shortest possible. I believe the best was actually a USB-A connector attached directly to a USB-B but that's obviously not doable for most. I use a 6 inch cable because I can, but have not "tested" audiophile 6 inch cables against this one at that's going to be a custom order and not returnable if I hear no difference. I would imagine I will be in the minority with not using audiophile USB cables.

I have read USB should be under 2 feet, there was some gobble-gook about why. I never compared, but since a shorter usb is cheaper anyway, I went with the recommendation. 

Common wisdom is that shorter is better (for USB cables, at least).

My experience is quite opposite. I have directly compared, at length, in my system, 1m against 2m:

- Supra cable: the 2m one had stronger and more authoritative bass, more drive, perhaps more highs; the 1m brought the mids more forward, the mids were more colorful, more enticing and the highs might have been slightly more refined. Overall I preferred the 2m one but I could imagine systems and ears for which the 1m one would be better

- Curious cable: the 2m one was clearly better on all fronts, no contest. The main advantage was, again, bass and the impression of a more dynamic sound