Anyone have an opinion about the Rti38 vs. Fxi30 when used as rear speakers in a 5.1 set-up. I currently have the Rti38's as surrounds. They sound great to me, however, I was considering upgrading receivers to a 6.1 or 7.1 set-up and using thr 38's as rear centers. That idea is out the window and I am sticking with the 5.1. Will there be a noticeable difference in the rear sound stage with the Fxi30's? I don't want the hassle of buying the Fxi30's to demo in my house and having to return them. Also, I can return the 38's to CC because I've only had them @2 weeks. Thanks for any input you guys can give!