Summary: I wanted to upgrade from the CSI4 but I didn't want to spend all that money for CSI6, at 225.00 can't beat the price and it is a beautiful, sound matched speaker to my other RTI speakers, (A3 fronts/A1 rears) excellent center channel, sounds great and purchased from Polk, so it's under warranty for two years.
Summary: I like most upper end Polk speakers and I do really like this one. It opens up when you supply clean power to it. I use an Adcom briged amp at 200 watts mono @ .09 THD. This speakers needs power to really open it up, my Onkyo 115 watt output did NOT do the job.
Summary: I purchased this speaker to replace an old Polk CS200 center speaker that had blown a midrange. Checked first with Polk to see which would go best with my 4 older, but still excellent Monitor 7Cs and 5JRs, and the CSi5 was the recommendation. (It is being discontinued and now being replaced by the CS6i, which is the current recommendation.) Soundwise, this is a perfect match!