It's fantastic, and resting comfortably at 9.6 on IMDB.
I wanted to just peek, not quite feeling up to committing to an entire bleak miniseries, but five minutes into the first episode I was hooked. I binged three episodes in one long night, then two late last night.
It's gripping and mostly true.
Only thing that bugged me is the English cast. Everyone is supposed to be Russian, but it sounds like Masterpiece.
Oh well, if that's the only nit across five hours, consider oneself fortunate to have found such an excellent production about a harrowing reality with a 24,000 year shelf life.