Thanks audiofreak. I find that putting diffusers on the front wall, behind the speakers, gives quite a bit more ambiance. Acoustic guitar sounds so much better now. It's tricky because initially cd music sounded bright and strident. I had to upgrade my equipment to get it right. But as the equipment breaks in, I'm really beginning to enjoy this experiment.
I like all the room treatments you got going and the CMU block for stands... nothing more "solid" than a concrete block. I put a ton of ATS sound panels in my room (mostly on the back wall) and two ATS "picture" sound panels on the front wall.... but I am thinking about doing a sound diffuser in the middle front wall, over the system. I have seen a bunch of videos about building your own diffusers... looks pretty easy, but time consuming to actually build.