Room treatment is necessary, and I know it equals the sum of its individual components. Acoustics are not as atrocious as they look. One side is open to the kitchen and the hallway. It's not the ideal room setup. But the upside is that there is no neighbor on that side of the house and no one in the back for 300 feet. With double-pain windows, I have no limit to how loud I want to play. The limiting factor is the eardrums.
That is a fabulous system, and so nicely put together. I can't stress enough about how much more you will get from it by adding a proper setup of room treatments. With all that you have spent on your system, a relatively small additional amount will likely yield benefits that far outweigh the cost. I highly recommend getting in touch with the very good people at GIK Acoustics. They will provide free consultation services, and you make the decision from there. Enjoy your system in good health.