There is a reason why XLR's can sound bright & edgy... it is because the noise removing/controlling circuitry removes 2nd order harmonics but leaves 3rd order harmonics. Unfortunately our ears like 2nd order harmonics but not 3rd order harmonics!
If unbalanced circuitry can control noise then unbalanced RCA ICs should sound superior to balanced XLR ICs... :)
If unbalanced circuitry can control noise then unbalanced RCA ICs should sound superior to balanced XLR ICs... :)