Interestingly enough, as much as I thought the show was going to be all about SEX, after they wrapped it all up with the second season, that's not its main topic. The first season was a rather 50 shades-type of fantasy, and it took a turn (or well, they elaborated and emphasized other aspects further) for the second season to tell about loss, marital problems, mid-life crisis, addiction, and to be a - in some ways - surprisingly candid and more or less realistic approach to people in their late 30s.
Most of the second season was honestly quite depressing. I don't want to see more into this series than what it is, but it was more profound than I anticipated it to be. I didn't think they would manage to wrap it all up, especially nicely, but they did, and I'm happy with how they left things.
What I didn't like at all is Sasha's painfully long and very extremistly parodistic/stupid "independent woman/extreme feminist" arc. As a (I'd say normal) feminist myself, to me, it felt as if someone dumb and clueless would try to come up with a feminist manifesto without actually talking to any woman in the world. I am aware that there might be people who would act like Sasha and her followers did, but the arc and the interviews with her as an author and empowered woman were a disgrace to feminism and empowered women. They could have at least resolved it earlier. Anyway, boyyyy, how Sasha and Kam look good together!
All in all, I liked Sex/Life for multiple reasons, and even though it started our as a regular 50 shades for mid-life crisis, it became a bit more. [spoiler] By the second season, I found myself caring about the characters, and rooting for Billie + Brad, and Sasha + Kam. I liked Majid too though. [/spoiler]