I would think that if I use only the analog 6 ch outputs, then I will only be using the DACs in the Denon, or I will be using the DACs in the Denon and also the DACs in the Yamaha.
You'd only be using the DACs in the Denon, not both (the Yammie will basically just act as an amp under this configuration).
What you could try is both ways - that way you can decide which DACs you prefer, sonically. Connect the coax and the 6-ch analogs. Watch a movie in 5.1, then switch audio inputs on the Yammie between the MCH and the coax ins. You'll probably prefer the DACs on the Denon... but who knows?
