The CS1 isnt even a close match to the R lineup of speakers from Polk.
It uses the same drivers the monitor(M series)line uses, which is much brighter sounding then the R's which are neutral to a tad warm in sound.
Plus it doesnt have the same cosmetic appearance the R's do.
The CSi20 and 25 use the same tweeters as the R's do, but not the same mid range driver and is the closest to the R series.
I run R30's for fronts and RT25i's for rears and had the CS-1 for a center and for movies its OK, for music it was piercing sounding over the 30's on the front so I went to a CSi25.
Ebay has these all the time, sub $75 shipped!!