In my opinion, balanced XLR connections are useless for Home Audio.The reason for going balanced is to eliminate cable artifacts.
There is a standard to which one must adhere to gain that benefit. It is often called 'AES File 48'. The point of it is not just long cables! That is a side benefit of the cables not imposing an artifact. Anyone that has auditioned single-ended cables to get the 'right sound' knows what I'm talking about.
The thing is, the equipment used has to support the standard. It sounds like the amp used in the opening post does not- it has a single-ended input and so there may be no benefit at all to using a balanced cable, since the cable will actually be operating single-ended.