No doubt your system sounds great, Luke. Thanks for the vids.
I do have a comment on the most recent slomo video of all four subs. I think it may be optical illusion, but depending on where I focus during the video, I find different things. I've thought the top two drivers were equally out of phase with the bottom two drivers, but in phase with each other, when looking at the top of the center speaker. I've thought the top left driver was out of phase with all the others when staring at the midpoint between the two drivers on the right. I've though the bottom right was out of phase with all the others, and significantly, when focusing on the light reflection on the top right driver.
Maybe I'm crazy, but try it for yourself. If it's of serious concern to you, a good way to see would be a direct-on camera view (from the front, equidistant from the stacks) with strong side lighting.
I'm going to put the cabinets side by side and really get the drivers moving.
From what I've seen so far I'm thinking I might have to RMA one of the baskets in the left cabinet.