I think the natural engineer intuition is that if a drug is just a chemical, and generic and name-brand drugs are the same chemical, how could there possibly be any difference? Don't be duped by advertising, save the money, be rational, etc.

One interesting case where there was a real problem was with generic extended-release bupropion (an antidepressant). The time-release mechanism on one of the generics didn't work correctly, although the manufacturer managed to get it past the FDA (they actually tested only a 150mg dose, and extrapolated the results to approve the 300mg dose).

https://blogs.sciencemag.org/pipeline/archives/2012/10/18/th...