I must be crazy. I just got an Onkyo TX-SR601 as an upgrade to my Panasonic SA-HE100 six months ago. Now I want to upgrade again to either a Harman/Kardon AVR525 or a Denon AVR3803. This will be my third AV receiver upgrade in a year. Am I nuts? I like my SR601 but at times it sounds a little harsh with my Klipsch speakers. I also want the ability to add a separate power amp later on if I want. Is this normal behavior or am I just a victim of the dreaded disease of upgrade-itis?