I got up to episode 3 this past weekend while watching it with my sister and her boyfriend. Both of whom have zero Witcher knowledge.
The boyfriend fell straight asleep into a snore somewhere in episode 2. My sister was holding on for my sake as I could tell she was lost beyond all hell but got into it by episode 3.
I'd say the first episode was good although you are trying to figure out whose who which was Okay for me (coming from W3 game), but for someone without knowledge, very rough. Then throwing out city/town names when a viewer with zero knowledge has no clue what they are talking about.
Episode 2 dragged. Had like zero action and was all convo which was Okay but even I got bored somewhere in there. Episode 3 brought me back and I thought it ended fantastic. Totally looking forward to the remaining 5 episodes which I'll get to on X-mas day.
All in all, they did a good job. The production values are high, the music was great. I didn't know much about the jumping between timelines until someone at work mentioned it and then it made sense. Odd choice that they would do that when you are trying to grab the audience who doesn't know much about Witcher and not confuse them even more.