I have two in-ceiling speakers for surrounds. This is paired with a set of BW 704s up front, no center and no sub. A HK AVR 430 does the signal processing and amplification.
In the future, I'll get a sub and BW ceilings -- in that order.
The ceiling speakers are not a well-known or great brand I'm sure but they came with the house. I was happy to get them calibrated to reference level which I was unable to do with a pair of JBL bookshelves I had laying around.
From an astethics point of view I like having them on the ceiling out of the way. This is a family room and not a home theater room so to speak. If I were building a true home theater for only that purpose I would not use ceiling mounted speakers.
I have no desire for 5 channel music -- so my surrounds are for movies and regular TV programming. For sporting events and your standard Dolby 2.0 broadcasts I enjoy the sound using Logic 7 Stereo or some form of 2->5 channel conversion.
I watched the Matrix yesterday on HBO (broadcast in DD 5.1) and I enjoyed what I was hearing.
If you want 5 channel music I don't recommend this setup. I like my music from the fronts only.
Comparing my setup to my parents which have a Sony HTIB application it isn't even close which I would rather listen to.
If you do get ceiling mount speakers I'd recommend an adjustable tweeter so you can give a bit of direction to adjust the sound.
If you've got someone you know who uses them go have a listen to your type of music/video.
