Regarding Atmos, I think if you have QS8s and perhaps the "right room", you don't need it.

My buddy and I were watching the Blu-Ray, Atmos season 5 episode 1 where the imp was inside the box struggling to get out. Holy shit! We were in that effin' box! The ceiling was coming down on top of us. We just looked at each other in utter disbelief, cackled and watched it over and over again. We couldn't believe it!

Now I know Atmos is extra channels that I don't have but I'm just telling you what we both heard. I actually didn't know it was Atmos until we were checking out the liner notes.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated