I don`t see the Butler 5150 either in your equipment listing OR in the pictures. You got some updating to do John. Boy that back wall partition`s gotta kill any symetry(mis) between your surrounds doesn`t it John? Definitely a job for 8th Nerve
If you're talking the post that is to the right of the couch, I'm sure it has some negative effect , but in general I don't notice much in the way of suppression of the imaging with the rear speakers. I'd love to remove it, but it might be what's holding up the entire second floor

What I'm wondering is if I should treat it with a "seam" piece. My other problem is there's no way to treat the first reflection point on the left wall, as it's a sliding floor to ceiling slat blinds, and the upper wall corners Bill mentioned needing treatment by my main speakers, I can do the one on the left, but there is no corner on the right, unless you consider the post going up to the stairs the corner; what's behind the speaker is a straight wall going 14 feet further down the hall to the front door. It's a tough room as I said previously.
I've been meaning to update my system pics for a couple of years now, but since I keep changing out gear so quickly I've not found a good stopping point to update

What I have now though should last at least a year

The only item that remains in my rig from those pictures is the Velodyne sub.