Is a McIntosh MA12000 a good fit for a Sonus Farber Amati Tradition?

Absolutely! Mac and Sonus Faber play very well together. The MA 12000 is a real gem in the McIntosh lineup. Check out some videos on YouTube of the Sound Sommelier, there you will find some great Mac/Sonus pairings.

How did the switch in speakers go? DAW and the Amati are on my list. Can you give me your thoughts?

I find that they work well together-the McIntosh 12000 and the SF Amati Tradition speakers. They are located in our main room, not in the smaller acoustically-prepared room where I had the ARC monoblocks and the Wilson DAW speakers. I love detail and timbre, so the new pairing is not as focused, but I can listen and move around more without losing the sound - I sacrificed focused listening with incredible detail for a sweeter, more generic sound. The one thing lacking is bass, and that may be a room issue, and I noticed that some folks add subwoofers to the Amati speakers, but that is too much for me. It has worked out to be a good compromise.