I own three of the Ling and three of the Ling single. I am using them in my Home Theater with a down firing Adire DPL12 transmission line Sub. I can tell you first hand the Ling are a bargain. They are unbelievable clear and do an outstanding job in a surround sound setting. In the movie "Ronin" you can hear the gravel spraying the cars during the car chase. They definitely add a level of realism to the listening experience. Even when playing without the sub the provide amazing base for a four inch driver.
The thing I've noticed about Klipsch is that they seem to have a frequency response dip in the mid-range which is the most critical area as human hearing is the most sensitive there. I suppose this is better than a peak. The RP-5 has a dip at 3kHz which gives it a "nasily" quality. The RB-75 has a huge dip at 3.5kHz. I don't know if Klipsch does this on purpose or what. The Ling speakers systems are "flat" throughout the mid-band with a slight rise at 10kHz. At this high of a frequency where hearing is less sensitive the rise is welcome as it gives the listener the impression of more "detail" and "ambience" but is not fatiguing. Of course, we're comparing $400/pr. for the Ling to $1200/pr. for the Klipsch.