Anecdote for sure, but we had a Niva on the farm I grew up on that basically lived it's whole life in a paddock, and even though the car needed to be roll-started when you wanted to use it (because the battery was the same vintage as the car) it was incredibly reliable.
The only repeat issue I've really seen with the old Nivas was rust as they allegedly spent months on snow-covered docks in Russia before being exported overseas, which ended up with them "coming with rust from the dealership".
I'm sure, however, that a professional day-to-day mechanic would have a different perspective on their reliability of course.
From what I heard Nivas that were exported from the Soviet Union went through more rigorious QA and were of a better quality than those released to the domestic market.
This was common practice in eastern block countries. They could not compete in western markets otherwise, even if the product was lower priced.
My only problem with the Niva is the fuel consumption, 19.6 mpg. Not something you'd want if you live in the EU. Otherwise it seems to be a quite reliable and repairable car. Also works with lower grade gasoline found in ex-soviet states.
The only repeat issue I've really seen with the old Nivas was rust as they allegedly spent months on snow-covered docks in Russia before being exported overseas, which ended up with them "coming with rust from the dealership".
I'm sure, however, that a professional day-to-day mechanic would have a different perspective on their reliability of course.