My experience has been, on the couple occasions I've heard them (always in stores), that the big k-horns have fabulous dynamic range and sound very realistic with instrumental music, but poor imaging.
Strange Klipsch thing
I stopped by a local shop this afternoon because the guy had recently set up a two channel room. At the moment he's carrying Cary amps - which I use at home - and Klipsch speakers. He had an SLI-80 integrated run through the big Klipschorn speakers placed in the corners. What I heard was an enormously wide soundstage with exceptional image height, BUT, the whole thing sounded like it was being projected onto a perfectly flat wall. Not so much as a shred of stage depth. Is this fairly common with Klipsch speakers? It really seemed like an odd effect. Not my cup of tea at all.