I've been watching the first two seasons on hulu. Made the mistake of getting interested in something at work, so I just finished up S2E5.
It's a little--not sure of the right term--soap-operatic (?) for my tastes. Overall I like it and will keep watching, but the side stories detract. Also some plot holes that bothered me. I'll spoiler just in case:
On the good side, I think that Jodie Comer is
fantastic. Love the way she can turn on a dime as the situation calls and become a different person.
Really like Kim Bodnia as Konstanin, he really seems to play the stereotypical Russian fatalist well.
Anyway, I think it stay in my regular rotation, but not something I'm going to buy the DVDs and rewatch or anything.