An advantage of the Orion is that they are tiny and light, sticking out from the camera body only about half an inch or so. The camera becomes extremely compact. I picked up my copy about 15 years ago for about $100 in Germany when Soviet equipment was flooding across the recently opened iron curtain.
A disadvantage of the Orion in Kiev/Contax mount is that you have to reach into the front of the lens barrel to change F-stops. That pretty much precludes being able to keep a filter on the lens (it takes a 49mm, if memory serves correct, but it must be extremely thin to avoid vignetting). Because of this, I tend to keep the lens cap on and just remove it when actually shooting (haven't forgotten to remove it yet). You have to remember to lock the camera mount at infinity before mounting the lens.
Mine is sharp, sharp, sharp, an excellent lens that I often carry if I don't want to be handling a lot of weight. I'm not a lens-test kind of person, but I never found any significant differnce in image quality between the Orion and my 1950s vintage Nikkor 28mm f/3.5 or, for that matter, an SLR 28mm Nikkor. Of course, the slow speed is a real limiting factor. I know that Leitz made a 28mm f/6ish lens in the 1950s, though I don't know if the Kiev is an exact copy of the formula.
I'm sure the CV must be a better lens image-wise and usability-wise. For that matter, a vintage Nikkor in user condition can probably be found for roughly the same price as a new CV 28mm. To make mine a bit easier to handle, I used a fine-tip marker to add measurements in feet to the scale focus (I'm not that good at estimating meters) as well as added some markings to indicate depth of field. I suppose you could do this with tape if you didn't want to make permanent marks on the lens itself.