I have a new Onkyo TX-SR603, and for the most part, it works great for me in my living room. I picked up the XM Connect and Play antenna, since my 603 is XM-ready, and I'm disappointed with the sound quality. DVDs, movies, even my iPod and regular FM radio sound better than the XM quality! I was really surprised. It sounds nowhere near as full or detailed as the other sound inputs. I connected it using the XM port on the back of the 603. Is so-so sound normal? Anything I can do to improve it? Is there a chance the antenna is defective or something? I tried all the various sound options with no real improvement.