Can't comment on the earlier Ref models, but my experience with the Ref 110 and the Ref 3 (driving Summits) is that they are, by far, the best sounding electronics I've ever heard driving MLs. That's not to say that there are other pairings that would also sound really good. I've been an ARC fan for most of my audiophile years and I've got to say that the Ref series of components really does it for me.