6/10 sounds about right, maybe even 5.5/10 for me. There was some good stuff, but... most of the rest just wasn't very good. And I'm not talking about timelines, those were confusing but I rather enjoyed how it all fell into place as more episodes went by. Although I'll say they could've aged Jaskier a bit more to show that 20 years went by between episodes 2 and 6; they had Yen mention that he has crow's feet now but that was it I think? Makes sense that Geralt and Yen had the same look as they don't age like normal folks.
So let me start with the good stuff (also I briefly played Witcher 3 and didn't read any books): episode 3 was amazing. If only the whole show was at that level, I would've praised it into oblivion. The fighting scene in episode 1 was also amazing, holy shit was that great to watch. The whole plot with Renfri was enjoyable too. The whole plot with Ciri and Calanthe refusing to give her up was also great, enjoyed watching Cintra fall because of how stubborn Calanthe and Eist were. The actress playing Ciri was very convincing too, good casting choice. Also I liked the actors who played the lead mages: Stregobor, Mousesack, Bork, Tissaia, all were on point.
For the bad stuff: episodes 2, 4 and 6 felt like they were from a second-rate fantasy sitcom, the only thing that was missing is the laugh track. The climactic scene with Pavetta in episode 4 was so bad I was torn between giggling and facepalming throughout the whole scene, just oof. Some plot points didn't make sense at all for me (big spoilers below). The doppler that got Mousesack said he acquired all his memories and experiences (and showed it to the audience saying how Mousesack though of taking his life so he can't be used), then he gets caught by Ciri because he didn't know the original Mousesack didn't like cold and had arthritis? Speaking of that, two children arrived at the forest of Brokilon scared out of their mind and the dryads made them drink the waters which kill folk who lie and bear ill intent, but when Mousesack arrives to take Ciri and yeah, Ciri said it's alright, so he doesn't need to drink the waters? Why introduce this plot point in the first place then? It didn't add anything except a plot hole. The scene which the whole first season led to, where Geralt meets Ciri? It's framed as if Geralt just walks into the forest to gather mushrooms or something and oh, there's Ciri! Happy reunion!
Also, the dialogue. I'm usually willing to make excuses for the unrealistic dialogue in fantasy shows but this show took it way too far. I can't count how many times during the show I thought "what the hell, people don't talk like that". I would've been alright with it if it was plot-relevant, but no, even the most standard dialogue mostly felt awkward as hell. I don't know. The show made me play the Witcher 3 again, and during the first three hours of the gameplay, the dialogue was better than it was in the show.
I will watch the second season, because there is a lot of potential in the show, and episode 3 shows it, but the execution is unfortunately lacking so far. There are some occasional sparks of brilliance, and I think Henry Cavill did a fantastic job and without him the show would've been even worse, but as of now this was an effort slightly above mediocre.
The "Toss a Coin to your Witcher" song and this recent Netflix map are dope af though.