Having a quick gander at your thread and thought I would offer a suggestion somewhat similar to what you were thinking about doing with the QS8. I was having a similar problem with my system and the dipoles I purchased

(yea it's not Axiom but the good people here let me stay as long as I contribute something worthy once in a while \:D )

Anyways the Dipoles just didn't sound right in the rear, there just seemed to be something missing - It was suggested to me to try and move the Dipoles to be used as rear sides and to try and use a pair of direct speakers for my rears to complete the 7.1.

That did it, that's exactly what was missing.