Hi Audiolib, thanks I was a little worried about the in ceiling rears but they actually worked out pretty well. Since I was having the ceiling done and insulated I figured it would be better space wise. Polk makes boxes to put the speakers in before you install them but they are sold separatlely and are not cheap- So the only thing special I did was just cut out the hole (or my handy guy did) and put them up there.

If they had been fronts or side surrounds I probably would have sprung for the enclosures but they sound pretty good up there. The tweeter is also 'aimable' so you can point it direcly at the sweet spot or away for a more diffuse sound.