I am wondering whether the 861 v6 is even necessary if I am happy with my 861 v4.2. I realize that I will not be able to get 8 channels but I had to reduce my set-up to 6 for the immediate futue. Hopefully, the upgrade path will be available when I need it.

861v6, DSP3100 x3, D1500, Revivers, DSP33 x 5