Al, many thanks for the info! I will check the link.
The Offramp 5 is still tempting me but I am not sure about the investment. The latest 2014V2 M7 firmware is good and I have almost decided to leave the Offramp 5 path. But I have some computer/USB noise related problem and I hope that one of these "USB conditioners" could help: I hear a high frequency noise if my M7 is connected directly to the computer via USB. The noise disappears if the M7 is connected via the DI-V3 coax (the DI-V3 is connected to the comp in this case). The problem is not really annoying because the noise is not present at the normal volume levels used for listening. But it is evident that something unwelcome is entering the M7 via the USB input.
If noise is the problem I would say that it could be on the D+/D- or the +5V of the connection. Taping the +5v pin might help, but my guess is it won't help much if USB32 lifts the +5V anyway. Similarly, the iFi might only help by providing cleaner ground, I think the ShortBlock similarly addresses ground related problems. In my system I find it better to leave the ground connected between computer and DAC/DDC, not saying that any of the ground tweaks wouldn't be helpful as I haven't tried them all. The Aubisque might work, but I would say it might be better to address the underlying problem.
Are you using the same wall power outlet for computer and DAC? Is this a laptop or PC?
Most of the USB transports will offer galvanic isolation from the computer, and might ultimately offer better performance than the USB32 depending how much you are willing to invest. I guess if some of the tweaks work well with the offramp then they can be carried over if you chose to use an external USB transport in the future.
Anyway I hope you get your noise problem sorted.