Harshness has been a pet peeve of mine as when I first got my current speakers I didn't realize they could be forward and bright sounding with the wrong electronics/cabling. I should say currently I have Paradigm Sig 6 version 2 speakers and Parasound (A21, P7) electronics with an Oppo 95 player.
I have pushed my system pretty loud with different tracks, and am quite happy with the sound, not hot sounding compared to the MA-1 at all. I'd say that the improvement over the MA-1 might be a touch warmer even. I talked to Mike Morrow personally(A very approachable guy who is willing to take the time for his customers) and asked him about brightness with the Eichmann silver RCA connectors. He said they wouldn't add any brightness over their regular connectors and he was right. That being said, if silver based connectors don't add any brightness, then the MA-3 with regular connectors wouldn't be an issue either.
No affiliation, but I respect a guy like that enough to mention it.