In a computer setup, where speakers are placed a good distance (a few feet) behind the location of the screen what is more important to good sound:
1) A center speaker that is at the right height with respect to the left and right speakers, but is occluded by the screen. Remember that this is an LCD monitor, not a projection sheet.
2) A center speaker that has an unoccluded path to the listener, but is not at the same height as the mains, though angled down.
Perhaps a better way of asking this is can Audyssey effectively deal with the sound change that you'll get from having a speaker that is occluded by a solid object?