Thanks so much for ALL the information. It's a lot to digest - especially being basically dumped into the middle of an unfinished house project and trying to think of everything I want done everywhere, all at once.

So, I'm thinking I'm liking a 2.35:1 AT screen, and in-wall fronts. I've been doing some calculations on speaker placement for 7.2.4 in my room space, and have a pretty good rough guide (until it's framed and I can get accurate measurements). Just need to find some 45 degree in-ceilings... and good in-wall fronts. Might replace my surrounds, although I do have 4 on-wall bipoles I might consider reusing (yeah yeah) and 2 or 3 subwoofers without new locations I could put into the space.