Could you explain to us what that reason is? I remember him describing the Mini II/ARC Ref610 combination as being the most realistic reproduction of small scale acoustic instruments that he had ever heard, or something to that effect, in the TAS Mini II review. I also think he auditioned the M5 with the ARC super monos in his home system, and perhaps the Q5.
I've always like SS with Magico, personally, which is why I use Pass Class A with my Minis. Spectral also sounds great with Magico.
We are talking many years back, but after the mini, I think he went on to review many hard to drive speaker, where ARC sounded like crap. Even being a reliable go to reviewer for arc (like Kessler), he could not honestly say it was good driving some of these beasts.