@jbhiller Glad you are pleased with your purchase. I smiled as I read your preliminary remarks. It very much parallels my experience and it should continue to impress.
My intro to Marantz intergrated's began around 10 yrs ago. I was driving Magnepan 1.7's with a well regarded hybrid 225wpc power amp. On paper, perfect match. But it just did not move me. I decided to redirect this second system towards a simpler integrated amp and purchased a Marantz PM-8005. My intent was to go with a speaker more appropriate for such an amp. I was floored when I hooked up this amp to the 1.7's Gone was the somewhat sterile and flat sound stage. The music now had a wholeness to it with a wonderful soundstage that I just loved. No edge whatsoever. And so began my Marantz journey.
The Ruby takes all these qualities to a higher level.
I find the Ruby fundamentally neutral but it does lean in a smooth, musical, and dimensional direction with very nice body and weight. But I never feel like I am lacking in "detail". To my ear, the musical color is saturated and beautiful.
I have used this amp in two different systems and the results are the same. I am most amazed in how it drives my Tekton Electrons SE's. The front baffle is only 28 or 30" off the front wall, so my soundstage expectations normally would be limited. But I am amazed by the large wall of sound that just washes over me. Now this is a tip of the hat to Eric Alexander of Tekton as well as Ken I of Marantz. This combo is synergistic. The Ruby is in no way put off by low impedance loads. Instead, it puts out ridiculous amounts of clean and controlled power.
Hope you continue to enjoy this unit.
P.S. I agree on the issue of front panel cosmetics. It is very nice overall for sure, but I sure would have liked a larger more impressive digital display for my aging eyes!