I bought my Kiev 4 from a second hand shop I'd entered with the intention of buying a sofa! For the price I assumed it wouldn't work and I'd have to get the tools out, but it functions as well as any camera I've owned. There was even a film inside. The only issue I found, common to most/all Kievs is a tendency to tear the sprockets on the final frame. I only did this on the first film, now as soon as tension increases I don't force things, and rewind. Remembering to manually set the frame counter helps. The advance knob is more highly geared than most cameras, and doesn't give the same feedback.
That aside it's worked beautifully. The rangefinder is correct in both dimensions, no squeaks, scratches or missing parts, the Jupiter 12 is also scratch and fungus free. Mine is mid-1970s vintage and any purchaser of a 40 year Leica should expect a CLA plus repairs - several hundred pounds. Research suggests Kievs built before the 1980s were mechanically superior to later models when quality dropped.
Quality relative to Leica is a moot point, the Kiev is a solid metal mechanical camera of vintage design, with the knobs and dials that suggests. There are no Barnacks with a 35mm lens for £20. A Kiev isn't for everyone and buyers may be unlucky, but the user experience is very similar to an old Leica. If a Leica is out of the question an FSU camera may be the answer.