Hi, Right now i have: Harmon 325 Receiver with JBL two N26's, two N24's and one N-center....not sure if this other stuff matters but, also: 65 Toshiba "HDTV HX Pioneer 563 Velodyne 10" How much of a upgrade is the Polk RTi38's and the center CSI40? My friend at Future shop can order me SIX RTi38's and the one CSI40 center for cost....which is half price. I only have 5 speakers now but i just got this Harmon 325 so i can have 7.1. So how much of a upgrade are the Polk speakers compared to the JBL's i have right now? Thanks a ton guys for any thoughts.