BALANCED is not DIFFERENTIAL
There seems to be some confusion or misunderstanding of balanced inputs and outputs.
A true balanced input (pins 2 and 3 of an xlr) rejects anything in common to those signal lines based on impedance matching, which must be carefully controlled in the cabling to be effective. In a balanced input the two signal lines do NOT have to be differential. In fact, only one of them has to contain audio if you don't want the 6db gain provided by differential signals. As long as those two signal lines are driven by an equal impedance and the cabling maintains a consistent impedance throughout its run, the balanced input will reject any signal that is in common to them, such as EMI, RF, clicks and pops, or whatever. Even the capacity of the signal lines can become moot in this scheme.
But a differential signal may not necessarily be impedance matched, or maintained along the IC run, and therefore does not have the advantage of common mode rejection at the input. Also, differential inputs may not necessarily be balanced.
Of possibly greater significance is the IC itself. A traditional balanced IC is a twisted pair inside a tight shield, as this is the easiest way to maintain a constant impedance from end to end. A so-called balanced IC that is unshielded and simply connects pin 1 to pin 1, pin 2 to pin 2 and pin 3 to pin 3 on the XLR ends, is NOT balanced. This is a worst case IC because not only is it not shielded (or is shielded in total, not just signal pins 2 and 3) its signal runs (pins 2 and 3) are not impedance maintained. Therefore at the balanced input its performance is anybodies guess. An unshielded IC with pins 2 and 3 wiring carefully impedance matched end to end MAY have pretty decent characteristics at a balanced input.
So there's a lot to consider when you argue about the merits (or not) of 'balanced' wiring.
My own take is that in all cases except simple short runs (some exceptions), true balanced differential wiring is preferred for accuracy and consistency of the signal. It also treats the + and - signal lines equally.
To me, unbalanced in general is flawed when connecting different chassis and internal chassis wiring topologies together because it treats the signal lines differently. The unbalanced 'hot' pin may be some exotic wire construction, but the other side of the signal (the return) is carried by a shield, a ground wire, or what have you, of a completely different topology. Some cables (MIT, Monster, several others) use the same conductor type for both signal lines of an unbalanced cable, and utilize a telescoping shield originating from the source but not connected at the target. That's an improvement. But in a system where there are many chassis interconnected, there can be multiple (and often different types of wire) connections which make subtle contributions to the return path (only) of all involved IC paths. I hope I'm explaining this in an understandable manner. It's a complicated issue and not easily resolved unless a system wide approach is made, which takes into account the internal grounding topologies of each piece of equipment, and how each piece is connected to power. (When using grounding power cables, there is yet another return path which becomes an influence on the audio return path). Proper balanced interconnects eliminates all of this.
--Bill