Yup, I'm about to watch 5th episode and I heard that the plot is going to be thicker since then.
I didn't play the game much, but I read all the books in the original language because I'm Polish.
Funny thing is that in my humble opinion the dialogs are the strongest selling point of novels and saga. Word fights between witcher and villains or his friends are as fast and tight as sword fights. A scathing and incisive (often offensive and hurtful ) replies are flying around and you just wanna clap your hands and scream "Burn!" all the time :)
I don't know about English translation, sometimes it is hard to translate idioms and wordplays from one language to another.
At this point, I'm like dudes who read Tolkien before the movies. I'll be never satisfied.
Anyway.
Episodes of tv series are getting better and better from the first one. Henry Cavill is veryveryvery ok. Joey Batey as Jaskier is cool. The rest... meh++. But fingers crossed, hope for better in the rest.
No idea about the books, but the dialogue is not great, and timing of delivery seems off. Hopefully it gets better - if not, there is hopefully some good fight choreography. :)