There are plenty more if you search in
reddit.com/r/askhistorians and reddit.com/r/Anthropology
So i'm not sure this debate is settled yet.
The second takes issue with his use of per-capita comparisons and suggests that an absolute rate may be a better measure. This is extremely silly and Pinker spends very little time discussing it because it really is absurd to entertain. For one, it implies the only true solution to any violence is massive population control. And two, it negates any comparison to cultural or behavioral change by simply pointing to the population size of the planet. Think of the statement, "Modern medicine has not advanced from the hunter gather days because more people under the age of 40 die every year than did 5000 years ago."
Edit: The second comment brings up a third point that the lower rate of violence does not imply we are better off, and is therefore questioning what we should define as violence. Pinker again readily addresses this issue by explicitly defining the type of violence he is analyzing, physical, and repeatedly stating that these issues are outside the scope of his book.
For example, in the first link the author summarizes his long comment: " In short, he's extremely sloppy with his numbers and relies on almost no scholarly sources. I would not accept the type of work he puts in from an undergraduate.". So maybe Pinker does jump to conclusions that not necessary result from the data.
The third point , about how do we define violence is crucially important. I wonder if you counted the homicide rate in nazi germany before wwii or in soviet russia after wwii , you've get much lower numbers than pre-history(per capita). But it's hard to tell with a strait face those are "better" or less violent than pre history.
Is he forgetting that Pinker writes mass-market books, not journal articles?