OK, I wanted to post what I did this weekend in hopes of getting some feedback on the process. It also makes for a good resource to come back to when I do this again.
My room is used mostly for movie and tv viewing and the goal was to optimize the listening environment for the "average" listening position.
Some things I know but can't help.
1) A corner isn't always the best place for dynamic subwoofer performance.
2) Seating close to a wall is not optimal.
3) Large openings to other rooms is not optimal.
Seating, sub, and speaker placement are pretty much dictated by the room. I'm dealing with it the best I can. Here's what it looks like.
Each colored dot on the couch represents a point of measurement. As you read through this post the color of a line in a graph corresponds with it's position on the couch.
So here's the steps I used:
1) Measure from each listening position.
2) Use the average tab in REW to calculate the Average (red) curve.
3) Use "Set Target" on the Average curve.
4) Move the mic around the room to find a position that produces a curve close to the Average curve. I call this the Testing Postion (black).
5) Use REW to suggest EQ settings but adjust by hand with BFD.
And now for the charts! FYI, I'm using a Hard-Knee House Curve.
The chart on the left is the baseline measurement and
the right is the corresponding "after adjustments" measurement.
Blue Position 
Green Position 
Purple Position 
Grey Position 
Orange Position 
All In One (for fun) 
Here's what the average looked like before adjustments.
After finding the average, I moved the mic around the room to find a Testing Position where the graph looked close to the average. Here's the Testing Position curve overlaid with the Average curve. It's from the black/red dot on the couch:
From here, I started to compute and input EQ settings. The first I settled on was a 6.5db gain at 20 Hz with a bandwidth of 3. During speaker matching, my SVS sub only needed to be at 1/4 gain to match the SPL reading of the mains. I could have also adjusted this on the sub itself with it's one PEQ setting, but chose to do it with the BDF. After running REW again after the 20Hz increase, I started tackling the peak at ~63Hz. An adjustment of -18db with a bandwidth setting of .25 helped it out. Then I adjusted the hump at ~94Hz (my x-over is set at 100Hz) and it took a -15db at .2 bandwidth.
For some reason I don't have the after adjustment Testing Position chart, but I do have the after adjustment Average chart:
It's not exactly perfect, riding below the target in the 50 to 80Hz range. I'm sure this is due to the excessive adjustments at 60 and 90. Also, when looking back at the After Adjustment individual charts, green, purple, and gray got better, but blue and orange got significantly worse. It took a lot more gain than REW suggested to get the Testing Position peaks to normalize. At this point I'm thinking I should simply take them out.
Ultimately, I need to go back to the drawing board on the filter settings, but I think the process is decent. With some trial and error I should be able to dial this thing in a little better.
What do you guys think? Is this process sound? Should I leave out the outlier testing positions (blue and orange)? Could the "center of a rectangular room" have something to do with the weird blue charts?
Thanks for your feedback.
-Jeremy