Spectron,
Thanks for explaining the pros and cons of the different mono-block configurations. The only thing I wasn't aware of, or didn't remember, was how the internal wiring is done to bridge the amps internally, as opposed of doing this eternally by the end user via an extra pair of ICs. It's clear now that the external connection will be the obvious one here.
I decided on not using internal connections mostly because of flexibility. I thought that I could have assemble a simple system in my office with the other amp, or if something ever happens to one amp, which I much doubt considering the built quality, I can keep going with one while the other one is out.
I'm not an engineer so I may be wrong here, but my reading of this is that the internal wiring will add to the signal path, whereas the use of the extra interconnect will not change anything internally for the signal, hence producing a shorter way for the signal to travel. Now that this is more clear to me, I'm even happier with my decision.
One thing that still puzzles me, and perhaps Spectron can answer, is why there is so much improvement with these amps in balanced mode. I know that based on the specs the power triples and the headroom doubles. In my experience with other brands however, more power alone and more headroom alone do not guarantee better and/or more efficient performance. I've heard another brand of amps in a similar configuration and I remember hearing more noise when the amps doubled, and a quieter sound with half the power. With the M3 SE, I hear the opposite. The sound is better timed, which yields better control of the silence between musical notes.
