My setup is below in the signature. I just purchased the CSi a6 and 4 Tc-60i's to use in my new homes "great room" theater.
My room is 18' long by 15' deep with 10' ceilings. The 55" tv is on one 18' long wall. The sub is to left of the left front. The fronts are centered on the tv and have about 8' of seperation. The center is above the TV angled down (15 degrees approx) to point at the main viewing area. The surrounds have 10' of separation and are 4' off the back wall. The rear surrounds have 6' of separation and are 1' off the back wall. The surrounds are centered on the TV and are in the ceiling.
I will have all of this setup in a couple of weeks. The builder is finishing up the house and I can't wait to move in. So please critique my equipment and setup with special attention to the fronts and sub. I would appreciate any advice that you would have.