@wyoboy - I have an Audioquest AC-14XL for my DAC and I have not noticed any obvious differences/improvements.
Before I upgraded from Chicago to Sydney interconnects I emailed Audioquest to answer some questions that had after reviewing their line-up.
The Bridges and Falls series are a single cable and the Rivers and Elements series are two individual cables (required for some setups) so the relative price point isn't an obvious indicator of quality across the series.
Their assessment was that Sydney would be a slightly better than Red River. Red River is superior to Golden Gate. They recommended Golden Gate ($80 for 1 meter) as being superior to Chicago ($100 per 1 meter).
My assessment is that I should have purchased Golden Gate over Chicago originally as a better value and think that Sydney is one of the better values when comparing price point to included design features.
I don't think that I'd upgrade from Red River to Sydney as I wouldn't expect a significant difference. Part of the reason that I chose Sydney is that it was about the most I'd be willing to pay. The Mackenzie is the next one up in price point and I believe that the triple-balanced design is optimized for balanced audio and they have just put RCA connectors on it because they can. They did confirm that all other things being equal, the double-balanced design is superior for RCA use and that their lines will be splitting as they have done with the Yukon.