So I thought I'd update this thread since a few things have changed in the last few days....
I bought the ARC GSi75 and was totally amazed at the sound quality. The sound was lush, huge midrange that easily filled the room, and amazingly 3D and holographic. The built-in DAC was truly reference level. The only thing that I missed was that it still didn't control the low end as well as I wanted to. There was a little bit of looseness and bloat that I just couldn't tame. Then a few days ago a used Luxman 590AXII popped up at a very reasonable price that I bought immediately. The goal was to compare both side by side and keep one. Both are well known and well reviewed so I knew it won't be difficult to sell either.
I've been listening to the Luxman for the past 2 days. The dynamics, clarity and transparency is absolutely top notch. Still I felt that the soundstage was not as wide and deep as the ARC, it was sounding a bit dry. I immediately missed the lush, big, all enveloping sound of my ARC. So much so that I was about to pack it up and put it up for sale. Then I realized that I was still using the Luxman stock power cord. On a whim, I grabbed my Cerious Technology Graphene power cord and replaced the power cord with it. I was not prepared for what happened next!
With the new cord, the Luxman opened up in a way that I did not think was possible. Suddenly, the soundstage was as big, wide and deep as the ARC. This amp has got my SF woofers by the balls and I'm getting the best bass I've ever heard in my house, so much so that I removed the REL subwoofer from the mix. There is so much texture and nuance to the bass that I just can't stop listening. And this does not come at the expense of resolution or any other sonic attribute. The dynamics, rhythm, midrange (although not as big as the ARC but by far the closest I've heard SS come to tubes), transparency, this amp has got everything I had hoped for and then some more.
It doesn't hurt that this is probably one of the most beautiful and elegant amplifiers I've seen. Looks much better in person than pictures. Yep, this is the end of my search!