I haven't read On Killing yet. I have it, but I ended up reading On Combat first. I also wasn't aware of the criticism or controversy over these books or the author. Based on what I've read so far though, On Combat is pretty spot for the mental preparation and training required to function in high stress situations.

I wouldn't want to vouch for every point, some of the book does get a little soft or preachy when he gets away from what I consider the core points. On that note, however, violent video games have been adapted by the military and police for training purposes. Some use the same basic technology as Duck Hunt more realistically clothed. The training systems work. Likewise, a soldier or policeman training with paint bullets and children shooting each other with soft air guns aren't doing anything fundamentally different, except that in the latter their isn't any prior training, systematic training goal or as Dave Grossman points out with video games, system of discipline. I've even considered using airsoft as a training tool for marksmanship or reflexive fire training. Whether or not the effects of media violence are as drastic as the author claims is up for debate, but the similarities between the games and the training systems are not. Do you think aapplying concepts from combat training to childrens' entertainment or letting children play games that are easily modified into effective combat training unsupervised is healthy?

I think the link between violent media and violence in society is probably pretty strongly related to parental involvement in their childrens' lives. Letting the computer, video console or television raise your children means letting a lot of random shmucks raise your children. Supervision undoubtedly plays a huge role. However, social commentary aside, I recommend you read the book for what it says about training for the high stress situation of interpersonal violence and then decide whether to apply the lessons to how you prepare for everything else.