I've owned many Klipsch speakers including the KLF-30 and CF-3 (ver. 3). I currently have a pair of Quartets in my bedroom system. They are built to a price point, and in that range, they offer a lot of bang for the buck.
With jazz vocals or acoustic guitar music at moderate volumes, the Quartets are sublime.
Everyone wants to crank them up. That's when their weaknesses become apparent, not just the brightness, but somewhat loose bass, and in the case of some models like the KLF-30 you'll hear the cabinets. With some modifications, the KLF-30s became really nice speakers and easy to listen to. Mods I did to mine included Crites tweeters, mids, and crossovers, dynamat on the horns, and re-gluing the back panel of the cabinets The CF-3s are one of the few things that I kind of regret selling. Of course it's been a long time ago and a lot of speakers later, so I may be romanticizing their sound a bit, but I really enjoyed those.
Someone has a pair of CF-4s for sale here locally and I've been having to talk myself out of buying them.