Let me jump in real quick...

What if he was going to be doing a 7.1 set up?

If the right QS8 were 6.5 feet up on the right wall, and the rears were on the back wall, would you recommend that the left surround (QS8) go on the back wall, on dangling from the ceiling?

How low woudl the speaker have to dangle from the ceiling to be Ok? Would 8 feet off the ground be ok (dangling from a 9 foot ceiling)?

Or would it be better the stand mount the left side surround?