I think so Karl. I've not measured it before or after so it's probably good old placebo at work, but I'm sure the bottom end is a lot tighter and my mixes are translating pretty well to other systems.
The other 2 corners are also trapped - one doubles as a vocal "booth" and the other corner is the door, with foam corner panels glued onto it so when I close the door, it sort of "closes the loop"
I did have 2 rugs on the floor but it was, to my ears at least,
too dead so I removed one to bring a bit of life back