Another Netflix show you say? Yes, another and another and another!! Netflix is producing some of the most interesting and compelling television out there. Let me get this out of the way right now. The OA is NOT like Stranger Things (as many reviewers, commenters, and watchers wanted to try to say). The shows could not be more different in tone, pacing, themes, almost everything other than having other dimensions (sort of?).
Okay, let me get into it without too much spoiled. I think you get more out of the show with very little knowledge of what it's about. Let's just say there are heavy metaphysical themes, questions of the nature of reality, explorations of near death experiences, and confrontations with fate. It's a SLOW burn though, so make sure you get at least 2-3 episodes in before you really judge it.
On non-spoiler praises, I think The OA does something that can only be done with Netflix. The story unfolds in sometimes broken narrative, jumping between different times of the main character's (Praire/The OA) recent past and the present. The pacing can be slow and it takes time for connections between everything to be made. In addition, the episode are all different in length, telling the story that needs told in the time it needs rather than smashing everything into a rigid time format.
This is a fascinating look at what television could be given creative freedom both narratively and structurally. I can't wait for a Season 2 if there is one.