On a scale of 1 to 10, this show is about an 8.4
I don't think you need to be an expert in Arthurian mythology to enjoy this show. I walked into this only knowing the basic legend/characters (such as Arthur, Merlin, Lancelot, and Guinevere. I didn't even know who the lady of the lake was before this.), and I was still able to fully enjoy the twists and easter eggs of the show.
Now the first 2 to 3 episodes of the series weren't the best and were a bit cheesy, but they weren't horrible as some other people here are making them out to seem. After you get through them, the story becomes highly engaging and makes you very invested in the outcome of the characters. For me, Merlin stole the show. I want to know more and more about him, and all the years he has lived through. I LOVED, L-O-V-E-D, the way Gustaf Skarsgård portrayed the mystical magician. In fact, I appreciate overall how magic is depicted in this universe. I also loved Dof. He made me smile most of the time he was on the screen. And I shipped him and Pym. Now, I think Katherine Langford did a great job as the Fey Queen. Nimue was a very interesting character with a lot of layers.
The cinematography was done well w/ the vibrant colors and intriguing shots, especially during the fight scenes. Because of this, I looked forward to all of the "Weeping Monk's " parts. The way the shots were done...Daniel Sharman made it seem so effortless while he was kicking everyone else's butts. Furthermore, I enjoyed the comic book transitions between the different storylines in each episode. That was something very new that I've never seen done before. The only thing I didn't enjoy was the CGI at times. Mostly in the first few episodes, it just didn't look high quality. But again, it gets better later in the series. It becomes less distracting as you watch along.
Overall, I would give the story building and settings 8/10. I felt like I was in the universe. They did well trying to explain a little bit about each Fey tribe and the diversity of the people. I just wish we could learn more of them and the prejudice they fought against. Hopefully, that can happen in a possible 2nd season.