I reckon John knows his stuff, Daphoid. Maybe because the dimensions of your room are not huge and you have QS8s rather than 4s...
My 8s are on the back wall about 25' apart and 8' up - it is not ideal. I was watching the latest Matrix flick a couple weeks ago, stood up to get a beer and the sonic violence 3' above the LP was tremendous - sat back down quickly and it was gone. Maybe I just need to bring them down a couple feet and use FMBs to get a little "toe in" (or sit on a stack of phone books).
Good luck. You can always move them around later.
