I would not say that there are clear and specific differences between Diodontidae and Tetraodontidae with regard to behaviour. In general Diodontids (the few available in trade) are comparable to Arothron puffers and not as aggressive as some other puffer species such as T. lineatus or the various piscivores. But results vary a lot from individual to individual.
Give a man a fish, and he'll eat for a day. Give a fish a man, and he'll eat for weeks.