For the most part I feel that it was very faithful to the old show with the roles that were filled.
As a child growing up seeing the odd episode here and there I remember being pretty annoyed with the Dr. Smith character. Honestly the actress that plays her did a phenomenal job in my opinion, but I kind of wish there were more redeeming qualities for her character throughout the show. I wanted Dr. Smith to be a bad guy that had issues that made them that way but still had some good. I got some of that while watching but overall most of what I got was that she was psychotic.
The family dynamic was a lot of fun to watch as well as the various romances as well. I hope that they keep moving forward and produce a second season.