I like the placement of #1 if QS8s are used at least for the sides. I am not sure of the results you'll get with in-ceiling.
On #2, it looks like the sides surround are a bit too far back but might still work well. I agree with Adrian in using direct firing for the rears. It might work better given the fairly big distance.
#3 seems to be the worst IMO. The rears are far back and the sides are in front of the seating position, in between you and the mains.


Bruno
M80s/VP180/QS8s/EP600/AVR-890
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"The problem is choice..."