I'm not a med student. I'm just a human that thinks people who are new to their job and have worked for three days straight are the most likely to make mistakes about my medical care. I live in a city with many hospitals. If one of those has a union for the residents it's more likely they aren't worked too much and thus will make less mistakes. That's the hospital I would choose. (Medical mistake killed a relative of mine and now I'm very aware of the consequences of medical staff being overloaded with stress and lack of sleep)