Hey Kevin, I just got in something you may be interested in trying with your new Spatials: Vicoustic Multifuser DC2 diffusers. They are 2D style ("skyline"), diffusing in both horizontal and vertical planes. I don't know if you are bothered by reflections off the sliding glass doors behind the speakers, but if you are, the DC2's should be of help. They come in a 6-pack, each panel 23.25" square by 6" deep. Available in white, grey, and black, they are made of very stiff, dense, hard EPS. U.S. dealers sell the 6-pack for $699, but you can get them from Thomann Music in Germany for almost $300 less, shipped. I love 'em!
Another product of possible interest: If you do a deep search on the GR Research/Rythmik OB/Dipole Subwoofer, you will eventually find a couple of Spatial owners who have been very happy with the bass augmentation the OB Sub affords their speakers. I'll try and find the location I saw their posts on---Eric.