Dean - specific question for you. If I do end up removing the upper VP150 center, I'll then have some room for height speakers. I MIGHT be able squeeze QS-8's above the screen, but they will be really tight. Seeing how you have played with height speakers a bit, what would you go with - in my room that is.
Michael based on the width of your room 12í, and what looks like a standard ceiling height I donít think the cost of QS8s would be justified especially if you are planning to put them in what looks like a recessed area above your screen. I think you would get more utility value out of a pair of M2s as height speakers or even mounting your spare M22s on their sides in that room (the driver orientation wonít matter with only ambient sound coming from the heights unless the two speakers are so close that you get interference).
What I found trying out different height speakers QS8, M22 and M2 was that having room for the sound to disperse out before being reflected toward me is what made the difference in the QS8s sounding better in the height role. I discovered this while trying different placements and realized that mounting the QS8s on the front wall required them to be almost equidistant from the ceiling and side walls. Here the QS8s didnít sound much different than the M22s or M2s. However as I moved them out toward the seating along the side walls it brought them closer to the peak in the vaulted ceiling and farther from the front wall with the distance to both now being very unequal. This made a big difference in how the dispersed sound from the QS8s spread around the room compared to the direct nature of the M22s and M2s.
The only reason I would go with QS8 height speakers in your present room would be to future proof toward moving to the larger 16 x 24 room you would like. Even then IMO a vaulted or at least high ceiling is a huge bonus with or without height speakers.
I also feel that a second center above the screen is more beneficial in most cases than height speakers, more so if you have multiple rows of seating that block a lower center from directly hitting the second or further rows.