When I saw Hard To Be A God I thought it was mind blowing, like nothing else... then I saw German's previous film which is very similar in terms of technique and style. It's weird but that sort of diminished both slightly in my mind, perhaps unfairly, made them less unique anyway.The other russians I mean Luposhansky, Aleksei German. I can stomach them as they're atmospheric and slow. Seen others I'm less keen on, festival type films, so not a great criticism of Sokurov. It says on wiki he was deeply influenced by Zerkalo. The other guy that worked with Tarkovsky, Konchalovsky, he took some of that atmosphere with him even when he went to Hollywood. Something in the Soviet water.
Mirror is one of my all time favourites.
Lopushansky is great yeah, he kinda hammers away at his post-apocalyptic theme but with enough to keep it interesting each time.
I'm also thinking Paradjanov and Ilyenko, not really Russian but surely related.