Agents of S.H.I.E.L.D. started out weak, But as it went on it only got better. As I am writing this review, the 5th season had already begun, and it is great. If you like science fiction and the superhero genres, I very much advice you to watch this show. For a TV show the CGI and effects are more then decent and the cast is great. The show does take place in the MCU, but they are usually doing their own thing and not getting involved with the movies, they may refer to some characters sometimes but they almost never do anything that effects the main movies of the MCU.