07-21-08: Blindjim
Lastly,
Just how much power is 'sufficient power'?
Well, I guess that depends on how big the room is and how much you want to jump out of your seat.
Most of my system is powered by 150w per channel. The rear surrounds (where the Omnisats are) have variously used 150wpc and 60wpc. Both did fine. The Omnisats are reasonably efficient for their size and can also absorb a lot of power (150w), so they're quite capable of making you jump.
I'd say a 60wpc system would make the Omnisats sound good because they sounded really good powered by an Adcom GFA-535 II, and anything from 100-to-150wpc with properly set up bass management (cross over to sats at 80Hz) would give you theater-level volume and transients or better in a medium-large (say, 18x20) room. That's my room size and that's what I get.
Anytime I've played a film on DVD/HD DVD with bombastic soundtrack (Lord of the Rings, Batman Begins, Harry Potter, Indiana Jones, Transformers), guests have commented how it sounds so much better than they've ever heard in a theater. I think it sounds as good as an Imax setup, but more seamless.