For the guns which were designed to use the Soviet-style steel-cased, lacquer-coated ammo, it works great. That's why you'll hear glowing reviews from the folks who use it in their military surplus weapons (AK-47s, SKSs, etc.)
For guns made to tighter tolerances, it can be a problem. And most modern handguns have tigher tolerance. The lacquer coating, when the gun gets hot, tends to deposit in the chambers, and the steel cases can lead to extractor failures.
When the has cooled and you try to extract a "glued" (perhaps unfired, but frequently fired) cartridge, you often have a problem. I've seen folks drive the cases out with wooden dowels. (They were prepared!)
I've not seen that's its particularly inaccurate, but I have personally seen it jam up several handguns... The lacquer is hard to clear/clean. Of all the folks I know who used to use it and swear by it, none now use it, and most swear at it...