I never liked the corner speakers but had gotten so used to them I had them off my list, thanks for stating the obvious. They also use cheap Sennheiser mics that are muddy, and I'm suggesting Shure 545SDs that are cheap and nice.
I'm going to take my floor standing
QSCs over there (well, they will come pick them up!) and we'll start with that and see the difference, then think about the room. They are fairly broke but I'm trying to talk them into 4x 2 way powered 12s like a Mackie or similar.
These would be hung from the ceiling and pointed away from the stage at an angle, correct?
If the corner traps were 12' tall and 3' square would that be enough to really help? Is there a diagram of this kind of thing somewhere?