Don basically agreed with these initial impressions of removing all of the absorption from the front wall. He thinks that it really took months for the ribbon drivers to break in and lose their initial edginess.
He agrees with me that maybe there's a little bit too much energy off of the front wall now, and that putting back a little bit of absorption, or experimenting with diffusion, might be worthwhile.
There is no way to prove it, so don't ask me to, but I really think that J.R. was on the right track to dampen the reverberation between the two closest parallel walls in the room near the ceiling. I might have thought a priori that removing all of the absorption from the front wall would result in an unhappy increase in brightness, but it hasn't.
I removed from the front wall four 24 inch wide absorption panels. I'm tempted to order two 12 inch or 18 inch wide absorption panels, and position them right behind the ribbon drivers, to reduce just slightly the energy reflecting off the front wall.