Interesting discussion. I had one year of private tutoring at Leningrad State University, during cold war times. But to be honest, I learned Russian mostly from just talking with friends. When I arrived there, I was probably an A1 according to your EU scale, above. When I left Russia, around 2 years later, I was around a B1-B2. My spelling, however, is atrocious because I have not written much in Russian. The chat on this forum has been a big help! And I appreciate all the corrections on my spelling errors.