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

@donquichotte Interesting - hopefully the longer cable works for me too - I just ordered a 1.8m USB cable from Zavfino - it's a standard length (returnable) and I assume (hope) there is a good reason why 1.8m is their standard length (other than it serves the average user in terms of distance between components).

The Uptone USPCB is ideal where it can be used, i.e. no cable but a printed circuit board. Otherwise a 10in Intona cable. Longer cables have reflections and may suffer from RMI/EFI incursions