Went from 5.1 to 7.1 w/purchase of my M60/500.
I had direct radiating speakers in my 5.1 Prefer the QS8's w/o a doubt.

You, like most of us, are cursed w/ a goofy room size/proportion/layout. The QS8's are very "placement forgiving," which directionals are not.

And, yeah, I'd consider the 80's. Your room is almost double the length of mine. Then again, where are you going to sit, relative to any and all drivers?

Always call the place you live a house. When you're old, everyone else will call it a home.