FINAL UPDATE:
I have all my acoustic panels in place and I made some measurements over the holiday weekend. Here are some photos and charts.




L and R with subs (1/3 smoothing)

L and R with subs (Psychoacoustic)

L channel separates (1/3 smoothing)

L channel separates (Psychoacoustic)

R channel separates (1/3 smoothing)

R channel separates (Psychoacoustic)

I have a high-pass filter in the signal path to my TU-8600S 300B amp. I have tube connectors installed on the amp and my GR-Research 24-strand speaker cables.
I like a little more bass so I have the volume turned up a little more on my subs, as seen in the graphs.
All of the diffusor panels (mostly PI Audio Group) have a few layers of paint, except for the skyline diffusors (Vicoustic) directly above the listening position.
The response is better with the curtains and blinds open. I know this doesn't jive with common beliefs, but that's how my room is.
Final thoughts:
I am extremely happy with the sound. I tried several different configurations that were suggested to me, but I found that the way I have the speakers positioned sounds best to me.
The imaging is great. Sounds come from very precise locations. These huge speakers actually disappear in the room. With the lights out late at night, they visually disappear into the black background of the diffusor panels.
Of course, there is always a downside. Here it is. These speakers expose the true quality of recordings. Some of the music I listened to in the past now sounds not-so-great. In fact, some of it sounds really bad and I don't listen to it on this system. It's fine in my car.
I encourage those who are building these speakers to post photos of your project. I know that I really enjoy seeing photos.
Thanks for everyone's help and encouragement while building this system.