A pair of them......wow! You'd better have EVERYTHING tied down.
I've only been able to watch one movie (Blackhawk Down) and listen to a little music. My impressions are:
1. HT impact is significantly improved. You now feel things much more in addition to hearing them. It is not however, over emphasized....just more visceral. In a word....awesome.
2. Music impact is more subtle. I've noticed it most at low levels. The Maestro adds bass impact and feel even at very low listening levels; the Force needed to be turned up a little more to get the sound going. My guess is that this is a function of the Maestro driver having a much larger surface area and thus moves more air with the same input signal level.
I'm sure I'll discover more over the next few months, but a major house expansion is consuming almost all of my free time.
John