BAT stuff and Cables

4yanx,
Balanced circuit tends to be less-depended on wire quality length and reactance i.e. gives you less options to "play with wires" and/or "audition" them. It's more versatile in all cases whether you're using long or short runs lowers noise floor and increases gain by few dB.

Added unbalanced connectors on newer BAT fully-balanced equipment can only add an extra noise especially if unbalanced cable is used.

If you buy directly from BAT, you can realy request the "old way" with only balanced inputs/outs as well.

When you bridge a balanced CKT to a SE input, you lost a few dB of gain. Also balanced CKT has better immunity for common mode noise, you lost it when you bridge it to SE. In other words, it will suffer more distortion from power supply coulping from energy dissipation across the spectrum. As for the sound, it would be less dynamic, less bass, not as accurate to my ears. Running in balanced mode, usually has more punchy bass, extended high, and gives more image/layers because of its lower crosstalk inside the spectrum. This is true for all balanced CKT designs not only for BAT. If you have balanced gears, just use balanced IC's.

Few more to add to the balanced circuit:
It is certainly more complexed so the manufacturers made pople believe that SE may sound much better.