I've never read the books, but am a big fan of the games (in fact it made me want to replay them all so I bought the bundle on Steam for the crazy low price of $4). I thought the series captured almost perfectly what I remember from them. Small things like Geralt's accent changing between British and American, Geralt using the wrong type of sword for the fight he was in, Triss not having red hair, and a very low number of monsters stuck out to me but they're pretty insignificant. What really stuck out in a positive way was the set and costume design, the cinematography, and the overall great acting. It took me a few episodes to figure out when they were showing flashbacks versus present day, but I really enjoyed that aspect. I'm officially hooked and can't wait for season 2.
To the "professional" critics, are you honestly good at your job if the general public flatly rejects your opinions? Constructive criticism is one thing, but it seems the critics today are nothing more than "those who can't" ripping on "those who do" and then patting themselves on the back for how knowledgeable of film making they are.