Quote

"They will have to be placed halfway between me and the screen. It's the only location available."
"I've mentioned this before and got a lot of negative replies on placement, but wouldn't it sound better this way than without any surrounds?" end quote

I think you might have been onto something with this....
I'd like to know how it went and your thoughts on the following.
I'm going to try moving my rear surrounds up to 65/75° and moving my rears to 110/115°, in effect I'll be swapping the locations. Because there is little info going to the rear surrounds and because its simple enough to swap the cables after I'd say its worth a try. This can go either way...