One point about development rather than new design
In the communist system and its hold over into the modern FSU it was hard to befall foul of your boss (s) or the organs by delivering - none delivery was a serious risk tho' Thus far safer to incrementally improve a working product than to branch out into something lovely and new . Hero if it works but risking "economic saboteur" if it fails. The Design collectives of course are no different to Boeing, BA or Dassault - lots of shiny new designs - but the power rest in the factories who are separate entities - where again, incremental beats new every day.
Its always interested me that the modern Japanese Navy takes the same approach - a steady rollout of new vessels but slightly modified after 2-4 built.