Always believed that cables mattered. However.......
I was convinced, mostly by others, that quality RCA was as good as XLR for shorter runs, the benefits of XLR only revealed by long runs. Purchased Mogami medium quality XLRs to run between ATC preamp and ATC powered floor standers replacing the Wire World Eclipse 8 Silver RCAs.
Hold the phone! Advice given was obviously wrong. Sent the World World back for re-termination and reinserted. Now it's all way better. Detail, dynamics, sound stage, attack.
I can be wrong and that's okay. Enjoy your XLR adventure.