Hello everyone: Was seeking some advice on purchasing an entire set of 7.1 speakers and Subwoofer. My local store demo'ed a set of Polk Audio speakers as follows: Front: LSI15, Center: LSIC Middle Surround: LSIFX Rear Surround: RC60I Subwoofer: PSW1000B Question1: Does anyone have any comments (+ve or -ve) about this setup? Question2: Would it be better to replace the Polk subwoofer above with the SVS PC Ultra? (it's about the same price). Do I need to worry about "Matching set" sounding better at all? Thank you!