Though I might have read it wrong, I believe Ralph's (Atmasphere) belief in using equipment that adheres to the AES standard is that it minimizes cable artifacts (sound differences). Given that recording studios use such equipment, and their cables can stretch of long distances, it makes sense to use it.
So, if your equipment follows the AES standard, then XLR cables will/should not 'color' the sound as much as RCA cables. (And, from my limited experience moving between Mogami and AQ, there was very little difference in sound quality).
If your equipment doesn't follow AES standards, then any cable you use would be prone to 'coloring' the sound. At this point, it doesn't matter how much you spend, as your cable becomes a tuning method. So, you'd have to audition to see what makes your system sound the best.
HTH
Bob