Harmonic Technology vs. Audioquest Cheetah

As one who previously owned both the HT PS MKII and Magic Link One's, I'd highly recommend you consider the Audience Au24 XLRs. New or used, the Au24s should be in the same or similar price range and may provide substantial sonic gains for you as it did me over these other cables you mentioned.

Remember, you can also request whatever cables you desire for a 30 to 60 day audition period of time. It's the best way to go unless you buy used.

-IMO

I have used both for an extended period of time. The Ht Prosilway III is a great cable and one I would recommend for most bang for the buck.
In comparison to the AQ Cheetah, the HT cable is a little warmer and not quite as defined. We're only talking a little here in a head to head. Without the head to head, I doubt if you would really notice it. In absolute terms, the HT would be what I would classify as a little more musical with the Cheetah being a more neutral and accurate cable.
The other thing ( and this could be system dependent certainly) is the HT presents voices a little farther back in the soundfield while the AQ brings them up to about the plain of the front of the speakers.
Both are excellent cables for sure. The HT is not real colored by any stretch and the AQ is pretty much right on in my system.
In some ways, I loved what the HT brought to the table but I also like the strict neutrality (or that ,"Cable is not there type of sound")of the AQ. Neither cable sounds silvery at all.
I would suggest this, if you system is already a touch warm, go with the AQ. If it is a little lean or thin, go with the HT.
With a bit of searching (Audioreference being one) you can buy the AQ for less than $500 for 1 meter RCA or XLR. The best price I have found on the HT was a fellow in Texas offering about a 25% discount or so.