I haven't heard the M60s or Silver 60 Monos, but I owned the Mid Monos for a while. I liked their sound quite a bit. They were silky smooth. I was using Penta Lab KT88SC's. I would have kept them if my speakers were more efficient, but I wanted more power.
If you don't get an answer to your question, why don't you contact Mike Sanders and ask his opinion. info@quicksilveraudio.com
If you don't get an answer to your question, why don't you contact Mike Sanders and ask his opinion. info@quicksilveraudio.com