As for 0's and 1's being transmitted, the high/low signaling does in fact represent 0's and 1''s. The separation of power may effect noise, but I contend that a cheaper cable operating within industry specifications absolutely will not sound any different. If there was data loss they would present themselves as pops, crackles, or dropouts. On average, digital links deliver one bit error for every 1012 bits sent. That's 1,000,000,000,000 bits. Keep in mind that there are only 5,872,025,600 bits on an audio CD.
I own Wireworld Starlight 7 (actually, two of them, A/B and A/Mini), and I can tell you there was a significant difference among all the USB cables I tried before WW S7. I tried a bunch of AudioQuest USB cables (up to $160 or so), Pangea Silver USB, and some others (including no name cables I could find at home).
Starlight 7 won this by a large margin (I still use both of them and love the performance). Second place took Pangea Silver USB, although performance wise it was easy to see the degradation (in cable world, it is not about the gain, it is all about losing the least about of signal possible, right?). Even higher priced AQ cables were not even close to the Pangea (I used to swear by AudioQuest cables but not anymore).
Now, why there was a difference?
First, my system could reveal a difference. Hopefully we are on the same page about this very obvious requirement. Audirvana Plus (Mac OS X) -> {USB Cable under test} -> Musical Fidelity VLink192 -> Kimber AGDL Silver Digital -> Arcam rDAC -> Kimber Hero -> Beyerdynamic A1 -> Beyerdynamic T90.
Second is not as obvious. As I see, a lot of people believe in this "digital is digital, it's either 1 or 0 and $1 digital cable will have exactly the same performance as $300 cable". I was there too (I have Masters in EE but was ignorant enough not to know some things).
Now, when I could clearly hear the difference, I got confused. What I believed in previously did not make any sense anymore, so I started digging into protocols.
So what I learned was that that most of the digital audio/video protocols are *lossy*. This includes USB audio streaming, S/PDIF audio (coax/optical connections), and even HDMI video/audio (hey, you probably thought this "digital" thing applied to HDMI video too? I did).
Look at this as a continuous stream of data (1/0) traveling from a source (computer) to a destination (DAC). Each data chunk is transmitted within a very small time slot. If it arrived as the other end in the same time slot, same 1s and 0s, everything would be perfect.
In real world though, perfect cables do not exist. Cheap cables lose some of ones and zeros on the way from source to the DAC, and generate some that were not originally present (signal reflections, for example). Yes, there is a check-summing in USB audio, but there is no retransmission of lost/corrupted data (no time for that; if the data did not make it within its time slot, it's gone forever).
Now, DAC gets this "digital" signal at the receiver end (which is not the same as at the transmitting end, subject to the cable's ability to lose as little data as possible), converts it back into analog domain, and we have a different analog signal already. Just imagine how (randomly?) wrong/missing/extra 1s and 0s could affect original message, and what DAC has to do in this case. Interpolate/extrapolate/apply some digital processing/you name it (so we can still have the sound without artifacts that one can hear)?
That's how we get slightly different sound (or video from a good HDMI cable). To be honest, this loss is not 50% loss, but it is there, and it is *large enough* so given appropriate environment we can detect it in a form of "this cable sounds different".
"What about my portable Hard Drive? I don't lose any data if I use a cheap USB cable!" Correct. Because USB works in a data/bulk mode, and in this case corrupted data is being retransmitted (your hard drive can wait a few more milliseconds while audio cannot).
I recently upgraded all AudioQuest HDMI Cinnamon cables and replaced with Pangea HD-24PCEe (4% silver) cables and what a difference it made. Not to digress, but USB audio is a similar beast, one just needs to be able to see what is out there (and not all of us want/can/care to, especially if one cannot find a reasonable explanation).