It definitely feels like the police in the US are generally less trained than those in most western European countries (or at least the one I live in), and while this doesn't necessarily make them more violent, it does seem to increase the variance in attitude and behavior I've experienced among cops in the US. There are those I wouldn't trust to use physical force even when necessary, and clearly others I would not trust to use force as a secondary or last-resort option. It's rather concerning when you don't know what you will get.
This is definitely not equally true of every department. I've lived in some smaller towns where the police are noticeably more compassionate, as well as some cities like SF where the presiding strategy seems to be avoiding the overuse the police partly because of their inherent unpredictability, an overly punitive justice system, etc.