Well, in my opinion, a good cable should just transmit the information without changing the sound quality. Which is why I use AQ.
The newest models by Garth Powell are, once again-IMO, the best AQ has ever made. I heard them at Audioconnection, and both my friend and myself noticed a distinct improvement in sound quality. I sounded so good, I ended up buying the William Tell Zero's and Bass for my systems. I also use the AQ interconnects between components, as well as for my ethernet.
As I have no experience with MacIntosh equipment, I can't say for sure it will be a good move for you. But, a good dealer, like John Rutan at Audioconnection, should be able to loan you a set to see if they do.
Bob