Soooooooo many possibilities...!

Audio Research Ref 6 has not sold me

Just curious; which interconnects did you try with the Ref 6? Did you run balanced or RCA? If you go to the Cable forum and read the recent "Balanced Cables" thread, there is some great information from Ralph of Atma-Sphere about the XLR pin standard and the undeniable fact that many amp and preamp manufacturers do NOT comply with the standard for various reasons, some good and some not so good. So, ARC, despite their lofty reputation and perhaps for very good, rock-solid reasons, does not comply with the established XLR standard (this is IF Ralph is correct-when I contacted ARC directly as a Ref 6 owner, they refused to comment!). If ARC had complied with the standard, in all likelihood the quality and design of the XLR interconnect would not matter that much but because they did not, it does matter. A lot. I have a Ref 6 and a Ref 150 SE. The manuals to each emphasize in unusually strong language that the owner should use the very best IC they can afford to extract the full potential of the two pieces. The manual does not make any distinction between XLR and RCA. The Ref 150 SE is XLR only, the Ref 6 offers both forms of outputs as you likely know. I tried five different XLR's at various price points and heard tremendous differences among them. 

I am a Manley fan and love my Steelhead. But I also love my Ref 6 and Ref 150 SE. But yes, the Ref 6 does push the sound out to the sides of the speakers, particularly when not yet broken in. This lessens with time but never goes away entirely and I can not disagree that for some, this is a fault and not a bonus.