AudysseyXT is pretty good stuff and works pretty well on my Denon x4400h. I know everyone is really hot on the new Dirac stuff, but I haven't heard it yet. I can't remember which models are eligible, but Denon was offering the Dirac software upgrade on either the x4700, or x4800 and up AVRs. There is supposedly some software coming out (Dirac and Trinnov) that could essentially correct for room modes by using active cancellation. It won't completely eliminate the need for sound absorption/correction panels, but it would greatly reduce it.