I have finally hung all the panels I ordered from auralex and I'm pretty happy. The "slap" has gone down alot. I may still need a little more upstairs, but I'm going to let it sit for awhile.
I really recommend adding padding if you have a hard room. It's easy to tell. Just clap your hands and listen for echoes. Reducing them softens the sound substantially. EQ cannot really get rid of this, so there really is no electronic way out of this problem. I have posted a few pics on the web site of the finished walls. Jump to
http://www.stabie-soft.com/speakers.html for a look.
Mike