When I visited, he had my Abbeys set up in his system with a Summa as center channel (his other two summas were just outside of the room, I helped him move them back into place after the demo but did not listen), and some other brand for rears...didn't really look. His subs were not of his design either, at that time. From what I understand, he now has Harpers for rears and Abbeys up front. He's said that Nathans are generally overkill for rear speakers.
Comparing a multi-channel system to a 2-channel system makes little sense to me, but perhaps you have your own reasoning behind asking.