I haven't made the plunge to ATMOS yet, but interested. I have a few questions. Is it worth the effort? I've seen ATMOS enabled 5.1/7.1 receivers, but they don't appear to have amps or pre-outs for the ATMOS speakers. How does this work? Which provides the best ATMOS effect, upward-firing or ceiling speakers? Which sounds better 2 or 4 ATMOS speakers. (room size 12x25x8).